Recommended Sections for Current Strand7 Users
Recommended Sections for Current Strand7 Users
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For users who are familiar with Strand7 R2.4.5, please go to Strand7 Release 2.4.6 for R2.4.5 Users to see a list
of changes made in the R2.4.6 release.
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For users who are familiar with Strand7 R2.4.4, R2.4.3 or R2.4.2, please go to Strand7 Release 2.4.5 for
R2.4.4, R2.4.3 and R2.4.2 Users to see a list of changes made in the R2.4.5 release.
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For users who are familiar with Strand7 R2.4.1, please go to Strand7 Release 2.4.2 for Release 2.4.1 Users to
see a list of changes made in the R2.4.2 release.
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For users who are familiar with Strand7 R2.3 and have yet to use Strand7 R2.4, please go to
Strand7 Release 2.4 for Release 2.3 Users to see a list of differences between Strand7 R2.3 and Strand7 R2.4.
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For a complete list of new features and functionality in Strand7 R2.4, please go to
What’s New in Strand7 Release 2.4.
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Strand7 Release 2.4.6 for R2.4.5 Users
Strand7 Release 2.4.6 for R2.4.5 Users
Introduction
The following list highlights some differences you may notice in R2.4.6 compared with R2.4.5.
New Features
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Displacement Scaling sub-stepping scheme is now available in the Quasi Static and Nonlinear Transient
Dynamic solvers.
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Nonlinear Transient Dynamic results file (.NTA) can be combined in Results/Combine Results File.
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Initial Base Velocity can be specified in the Base Acceleration dialog of the Linear and Nonlinear Transient
Dynamic solvers. This can be used to synchronise the initial velocity conditions with the initial accelerations.
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Strand7 Release 2.4.6 for R2.4.5 Users
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The Fillet Plates tool has a new option Stitch Plates. If this option is set,
the selected plates will be modified to connect to the fillet plate, if possible.
Otherwise, the fillet will be created but will not be connected to the
selected plates.
Stitch Plates = ON
Stitch Plates = OFF
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Tension Contact can now be set to include or
exclude Lateral Stiffness.
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Strand7 Release 2.4.6 for R2.4.5 Users
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New option Establish quasi-static stress state at time = 0 for NTA under Solver Defaults/Creep. This
option is set by default.
If set, the initial state of stress is established based on the static loads at time zero. The stresses due to the static
loads are then used to calculate the initial creep strain rates at the instant the time history starts.
If not set, loads are assumed to just start at time zero, and therefore the initial creep strain rate will be zero. The
creep strain rate will then develop as the stress in the model increases.
In a nonlinear transient dynamic analysis, if a model is not restrained and is relying on its inertia for stability, then
this option should be cleared as its quasi-static solution is singular. Alternatively, a nonlinear static initial conditions
file can be specified to establish the initial creep rate. If the initial creep rate can be considered to be negligibly
small, and the initial state of stress can be ignored, then no initial conditions file is required and the solution can
proceed by clearing the option.
This option is not relevant if Creep is not included in the solution.
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New option added to Edit/Delete for additional flexibility in deleting attributes.
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Strand7 Release 2.4.6 for R2.4.5 Users
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Creating a sub model from staged or unstaged nonlinear analysis is now possible. The sub model will contain a
series of load cases corresponding to a series of freedom cases. Each load case/freedom case pair corresponds to
each load increment of the initial solution. The enforced displacements introduced are incremental
displacements, which only make sense when run using the staging sequence automatically set up by the sub
model tool.
This means that the whole loading history is captured in the sub model. However, when morphing is used, the
effect of the morph operation between increments may not match the original model because the sub model is
unable to consider morph effects from elements that have been excluded. For significant morphing displacements,
the sub model approach is not recommended.
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New Plate RC option Add reinforcement to limit compressive strain. If selected, reinforcement may be
added when the concrete compressive strain exceeds the allowable limit. This option is only available when
compression reinforcement is allowed.
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Strand7 Release 2.4.6 for R2.4.5 Users
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For the elasto-plastic iteration method of the RC module, the convention for concrete strains has changed: now
concrete strain in Layer i refers to the strain on the surface nearest to Layer i, in the direction of the Layer i
reinforcement.
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The Online Editor now includes the option to list node coordinates when viewing node attributes.
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New option Apply to deformed display is available when setting reference displacements (Results/Reference
Displacement). In addition to reading and plotting relative displacement results in peek, listings, contour and
graphs, the deformed display of the model (due to non-zero Displacement Scale) can also be adjusted to show
relative displacement. If this option is set, the Displacement Scale will use the relative nodal displacements to
draw the deformed shape of the model. If not set, the Displacement Scale will use the actual nodal
displacements to draw the deformed shape, but displacement contours, peek and listings will show the relative
displacements.
General Changes
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The Node and Vertex Symbol (View/Entity
Display) can be cleared such that nodes and
vertices are drawn with no symbol.
This can be useful for drawing node attributes on
free nodes without showing the node itself.
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The energy flow rates at the node, Node Flux results, have changed sign. Positive node flux is inflow and
negative node flux is outflow.
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Strand7 Release 2.4.6 for R2.4.5 Users
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The Select/Plate Faces and Select/Brick Faces operations have been simplified to allow easier selection of
entity faces and/or nodes lying on the entity faces:
If Node Select is set on the main menu, the nodes on the target faces will be selected.
If Plate/Brick Select is also set on the main menu, the element faces will also be selected.
If only Plate/Brick Select is set on the main menu, then only the element faces will be selected.
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When switching between freedom cases throughout the staged analysis, any freedom cases introduced at later
stages will be initialised at the current position in that stage and enforced displacements applied in newly
introduced freedom cases are treated as incremental displacements from that stage onwards. For example:
Freedom Case 2
(DY Node Stiffness)
Load Case 1
(Force X)
Freedom Case 1
(All Fixed)
Solving the model produces the following results based on the staging sequence described below:
1. Freedom Case 1 is active whilst Freedom Case 2 is inactive. The model deforms due to the applied loading.
2. Freedom Case 2 (DY node stiffness at the top) is introduced at the current position. There is no change in
results since there is no load increment and no enforced displacement increment.
3. The loading is doubled whilst the top of the column is still restrained vertically by the node stiffness in
Freedom Case 2. The node stiffness now produces a reaction vertically upwards.
4. Freedom Case 2 is deactivated and the column bends further due to the increased loading and the fact that
the node stiffness (spring) has been removed.
5. Freedom Case 2 is re-introduced at the current position. Again there is no further change in results since
there is no load increment and no enforced displacement increment. The node stiffness is not loaded (i.e.
the vertical reaction will be zero at the top of the column).
6. The load is removed and the column springs back a little. The node stiffness is now producing a reaction
vertically downwards.
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Strand7 Release 2.4.6 for R2.4.5 Users
This stage dependency applies to the following freedom case dependent attributes:
Node restraints/enforced displacements
Node stiffness attributes (Translation and Rotation)
Node damping attributes
Beam, plate and brick supports
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The Attach Parts dialog options have been rearranged and reworded for more
clarity.
New API Functions and Changes
Please refer to the Strand7 R24 API Manual.pdf for more information.
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New API functions:
St7SetTransientBaseVelocity
St7GetTransientBaseVelocity
St7SetDisplacementScale
St7GetDisplacementScale
St7SetEntityContourFile
St7GetEntityContourFile
St7AssociateResFileStage
St7SetGroupColour
St7GetGroupColour
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Updated API functions:
St7SetPointContactData
St7GetPointContactData
St7SetSolverLogicalParameter
St7GetSolverLogicalParameter
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Solver parameter spDynamicAutoStepping is now used with St7SetSolverDefaultsInteger and
St7GetSolverDefaultsInteger.
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New/Updated API constants.
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Strand7 Release 2.4.6 for R2.4.5 Users
Solver Improvements
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Improvements will be noticed in all the nonlinear solvers in terms of better convergence and increased stability.
For staged analysis, the birth of beam elements parallel to, or nearly parallel to, the global Z axis now produces
more predictable initial orientations that are very close to the orientation defined in the pre-birth element.
For Inertia Relief analysis, improvements will be noticed in the removal of rigid body motion.
File Import Improvements
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Import of geometry files in IGES, STEP and ACIS-SAT has been improved further.
The DXF Importer includes various improvements and now supports the import of splines and ellipses.
Ansys Exporter has been improved with the addition of plate offsets and element non-structural mass export.
Other Improvements
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Automeshing improvements will be observed in many cases.
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9
Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
Introduction
The following list highlights some differences you may notice in R2.4.5 compared with previous releases.
New Features
In selection mode, dragging the mouse in a model
window will define the selection region by a solid line
rectangle and all visible entities within the region will be
selected. However, this mechanism selects only visible
entites; it cannot be used to select entities that are fully
obscured by other entities.
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A new selection mode is available to select all drawn
entities within a region even when they are
obscured. By holding both Alt + Ctrl keys at the
same time as dragging the selection window, a solid
double line selection region will be shown,
indicating this new selection mode.
New options to Expand and Collapse are available when right clicking any
Group tree.
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New Brick Targets options, Free Faces or All Faces, are available in the Tools/Attach Parts dialog. The All
Faces option allows attachment points to be established within a brick mesh, not just on brick free faces.
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
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New option is available to list all file types in the Browse window of the
Results/Open Results File and Results/View Results Log File dialogs.
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New Solver Defaults/Sub-Steps parameter
Maximum MNL Fibre Strain Increment for both
static and dynamic solvers.
See help file for more information.
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Iteration Limit control is now available for Steady
State and Transient Heat solvers.
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New Wedge Subdivision options, Use A and B or Use A and C, are added to the
Tools/Options menu Subdivide tab. This option increases the flexibility in global
subdivision for models that contain both hexahedral and wedge elements, especially
when the brick mesh has been extruded from a Quad and Tri plate mesh.
The triangular faces of a wedge element are subdivided using a single subdivision parameter
A. By default, the parameter B sets the number of divisions along the quadrilateral
direction. Now you can select whether B or C should be used for the quadrilateral
direction.
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The following characters are now supported in strings evaluated to numbers. For the full list of supported
variables and operators in equations, see the Essentials/Entering numeric data topic in the help file.
Operator
Description
¼
Evaluate to 0.25 (ASCII 188 character)
½
Evaluate to 0.50 (ASCII 189 character)
¾
Evaluated to 0.75 (ASCII 190 character)
–
Same as Subtract (ASCII 150 character)
—
Same as Subtract (ASCII 151 character)
-
Same as Subtract (ASCII 173 character)
÷
Same as Divide (ASCII 247 character)
×
Same as Multiply (ASCII 215 character)
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
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New Solver Restart File
option Save only last
step (Minimum size).
See help file for more
information.
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The surface automeshing option Skip Transitioning changes into
Apply Auto Transitioning and a new Consider Nearby Vertices
option is added.
The Apply Auto Transitioning option allows transition gradually from
smaller elements towards the nominal mesh size requested by the user.
Features and edges that are smaller than the nominal mesh size will
influence the local mesh size and their effect will be felt a certain
distance from the feature itself. When this option is not set, the
automesher will attempt to transition immediately to the nominal mesh
size irrespective of small edges and other features (this usually leads to a
more uniform mesh).
If Consider Nearby Vertices is set, then vertices that are close to, but
not attached to a face, will influence the local mesh size on the face.
This option is only active when Apply Auto Transitioning is set. The
option is also available in the Custom tab.
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
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For Quasi Static and Transient Dynamic
solvers, under the Moving Load section, a
new option Automatic Load Path Divisions
is available to automatically set the number of
load path divisions such that all vehicles in the
load path will at least travel from one division
to the next within a time step. This increases
the accuracy of positioning the vehicle on a
load path.
The number of load path divisions used by the
solver is noted in the solver log file.
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In construction sequence analysis, the birth stage
coordinates of the morphed/unmorphed
elements are now reported in the Results/Peek
tool.
New nonlinear transient dynamic solver
Defaults/Sub-Steps option, Predict
Contact Impact.
This option allows the time step to be reduced
if necessary, to ensure that the onset of contact
is captured.
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New option Use results case
names when importing the
temperature distribution from heat
transfer analysis.
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
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New option Use existing In-situ
attributes as initial conditions to take into
account any in-situ attributes already
assigned to the elements for the Tools/Auto
Assign/Soil In-situ Stress calculation.
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New Reinforced Concrete results quantity – Wood-Armer Forces. As conventional design of reinforced
concrete considers only the moment at a section, the membrane forces in the slab are typically ignored, or a
correction is applied to the moment calculation to account for the presence of membrane stress. In Strand7, the
Elasto-Plastic Iteration method for RC analysis has the option to consider membrane forces. The same WoodArmer transformation is used for the plate membrane forces as is used for the bending moments. Refer to the
help file for more information.
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New option Apply Dynamic
Factors in the Global/Load
and Freedom Cases/Seismic
Load Cases dialog to consider
the dynamic factors assigned to
the selected non-structural
mass when used in the quasistatic seismic analyses.
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
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Update and Auto Update
buttons are added to the
Summary/Attributes window.
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New Results Options under Other tab,
Consider Element Offset in
Displacement Results. If this option is
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set then the element displacement results
will take into account the offset distance
(if applicable) and the node rotation to
calculate displacements at the element
surface. Note that node displacement
and element displacement results are the
same if the offset distance is zero.
New Soil Element Stress settings to
specify the stress results type for soil
elements: Total Stress = Effective Stress
+ Pore Pressure.
Import of SAP2000 TABLE: "AREA LOADS - UNIFORM TO FRAME" is now supported.
New SAP2000 import option Merge Duplicate Freedom Cases is available to reduce the number of duplicate
freedom cases.
Import of NASTRAN PCOMPG card is now supported.
Import of ANSYS *GET command is now supported.
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
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New Time Delta and Time Sum
columns in the Time Step Editor
show the time increment in each
row and the total time up to each
row.
Solver Defaults Save TableInserted Steps option under
Sub-Steps section is moved to the
Time Step Editor dialog.
New right-click menu
option Retrieve Modal
Damping, automatically
enters the effective
damping ratios calculated
from the Natural
Frequency solution into
the Modal Damping field.
Applicable to Harmonic
Response, Spectral
Response and Linear
Transient Dynamic
analyses.
New/Updated Libraries
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The following ply material libraries have been updated:
Advanced Composites Group - Aramid Fibre
Advanced Composites Group - Carbon Fibre
Advanced Composites Group - Glass Fibre
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Glass material library has been updated.
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SHS (350 Grade) section libraries have been updated.
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The following beam section libraries have been updated as per The Red Book 7 Edition:
th
South African - Angles (Equal Leg)
South African - Angles (Unequal Leg)
South African - Channels (Parallel Flange)
South African - Channels (Taper Flange)
South African - Circular Hollow Sections
South African - Cold Formed Angles (Equal Leg)
South African - Cold Formed Angles (Unequal Leg)
South African - Cold Formed Channels
South African - Cold Formed Lip Channels
South African - Cold Formed Top Hat Sections
South African - H Sections
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
South African - I Sections (Parallel Flange)
South African - I Sections (Taper Flange)
South African - Plate Girders
South African - Rectangular Hollow Sections
South African - Square Hollow Sections
South African - Structural Tees
General Changes
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Coefficient of Thermal Expansion vs
Temperature table definition update:
Mean:
ε (Tc ) = α × f (Tc ) × (Tc − Tref )
Instantaneous:
ε (Tc ) = α × ∫
Tc
Tref
f (T ) dT
where:
ε (Tc)
Thermal strain at temperature Tc.
Tref
Initial temperature.
α
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Material thermal expansion coefficient
at initial temperature.
The pre- and post-processor now uses up to 3GB of RAM like the solver.
When Fluid elements are used, the mass matrix is automatically set to Consistent.
When Soil elements are used, if the void is filled with fluid with non-zero density then the fluid mass will be
included for both static and dynamic analyses. For example, additional weight due to fluid content is generated
when global accelerations/angular velocities are applied; for dynamic analysis, the mass of fluid is added to the
element mass matrix.
The Zero Eigenvalue edit box under the Solver/Defaults/Drilling page is removed. The drilling suppression
procedure has changed such that the Zero Eigenvalue is no longer necessary. See help file for more
information.
Maximum number of plate layers in the Plate Property Nonlinear Tab is now 100.
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
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Solver Defaults parameter Zero Point
Force under Elements section is
removed.
Solver Defaults parameter Zero Force is
added to the Iteration section.
When the norm of the residual forces is less
than this value (1E-3 N by default), the
Residuals Norm Tolerance is considered to
have been satisfied. Note that the Zero
Force parameter has units of force, and
allows the solver to continue when a very
small (or zero) load has been applied.
This is similar to the Zero Displacement
parameter; when the norm of the iterative
displacements is less than this value the
Displacement Norm Tolerance is considered
to have been satisfied.
The increment, sub-increment or time step is
assumed to have converged when both
Displacement and Force Norms are satisfied.
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Rotational mass of torsion truss elements can now be considered in the mass matrix.
Both Thin and Thick Beam formulations can now be considered in the linear buckling analysis. The geometric
stiffness matrix is automatically set depending on the values of shear area defined in the beam property.
Definition of Plate RC results quantity Concrete Strain for the elasto-plastic iteration method has changed.
Concrete Strain gives the minimum (most compressive) strain in the concrete when the slab is being reinforced
in a given layer. For example, Concrete Strain – Layer 1 means the minimum strain experienced by the concrete
when the applied actions are being resisted by reinforcement in layer 1; typically this occurs on the
corresponding layer on the opposite side of the slab, i.e. Layer 3.
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Formula is printed in the Rayleigh Damping
dialog. Additionally, when the frequencies and
damping ratios are entered, the alpha and beta
constants are automatically calculated and can be
edited if required.
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The dynamic rotation origin is reset to centroid when a Redraw operation is performed (e.g. the F3 key is
pressed).
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
New API Functions and Changes
Please refer to the Strand7 R24 API Manual.pdf for more information.
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New API functions:
St7SetPropertyCreepID
St7GetPropertyCreepID
St7EnableSaveLastRestartStep
St7DisableSaveLastRestartStep
St7ShowSelectionToolBar
St7HideSelectionToolBar
St7SetSelectionToolBarPosition
St7GetSelectionToolBarPosition
St7DeleteGroup
St7GetInertiaReliefResults
St7SetPlateLayers
St7GetPlateLayers
St7EnableAutoAssignPathDivisions
St7DisableAutoAssignPathDivisions
St7EnableModelStrainUnit
St7DisableModelStrainUnit
St7EnableModelRotationUnit
St7DisableModelRotationUnit
St7SetQuasiStaticRestartFile
St7GetQuasiStaticRestartFile
St7SetNodeHistoryFile
St7GetNodeHistoryFile
St7GetRCUnits
St7SetRCUnits
St7EnableModelRCUnit
St7DisableModelRCUnit
St7GetTotalCreepDefinitions
St7GetTotalLaminateStacks
St7GetTotalLoadPathTemplates
St7GetTotalReinforcementLayouts
St7GetCreepDefinitionNumByIndex
St7GetLaminateStackNumByIndex
St7GetLoadPathTemplateNumByIndex
St7GetReinforcementLayoutNumByIndex
St7GetCreepTimeUnit
St7SetCreepTimeUnit
St7GetCreepConcreteLoadingTimeUnit
St7SetCreepConcreteLoadingTimeUnit
St7GetCreepTemperatureInclude
St7SetCreepTemperatureInclude
St7GetInertiaReliefResults
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New/Updated API constants
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New API sample projects and headers for C# 2010.
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New API sample projects and headers for Python.
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Strand7 Release 2.4.5 for R2.4.4, R2.4.3 and R2.4.2 Users
Solver Improvements
Solver improvements will be noticed in the following:
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Convergence of most nonlinear problems.
Reduction of time required to determine nodal reactions in large clusters of links.
Geometry and Automesher Improvements
Improvements will be noticed in the following:
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Support for a wider range of surface types.
Increase in speed and reliability of automeshing.
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Strand7 Release 2.4.2 for Release 2.4.1 Users
Strand7 Release 2.4.2 for Release 2.4.1 Users
Introduction
The following list highlights some differences you may notice in R2.4.2 compared with R2.4.1.
New Features
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The Dynamic Rotation mode can now be activated via middle mouse button in addition to F4 function button.
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Update buttons are available in the
Summary/Model, Mass tab.
This is used to refresh the summary page after changes
are made on this tab. This is useful for large models so
that only one update is required after changing multiple
settings.
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Update buttons are available in the
Results/Listings.
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In the Results/Peek window,
right-click menu on the
show/hide quantity area is
available to quickly toggle the
column state.
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Strand7 Release 2.4.2 for Release 2.4.1 Users
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In Attribute/Plate/Attachment/Edge and Attribute/Edge/Attachment, a new option is available to set the
attachment direction. The +z or –z attachments can be useful in situations such as welded doubler plates where
the attachments are only required around the edges and in the direction normal to the plates.
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Initial Conditions for Nonlinear Transient Dynamic solutions can now include both an Initial Conditions File
and the Initial Velocity definitions from a load case.
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New parameter, Sticking Friction Factor, is introduced in the
Nonlinear Solvers, Defaults tab, Nonlinear page.
This is used when the contact element has friction, but is not sliding.
In this situation, the lateral stiffness (frictional tangent elastic stiffness)
is set to be the product of this factor and the initial axial stiffness of
the point contact. Note that the Dynamic Stiffness option affects
only the axial stiffness of the contact, not the lateral stiffness.
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Strand7 Release 2.4.2 for Release 2.4.1 Users
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New option, Save Table-Inserted Steps, is introduced in the Quasi
Static, Linear and Nonlinear Transient Dynamic solvers.
Set this to consider saving the results for any additional time steps added by the
Factor vs Time tables selected in the solver Load Tables. If the Add Time
Steps option is set for a table, then additional time steps will be added to the
solution. If the Save Table-Inserted Steps is set, these additional time step
solutions are then saved to the results file according to the Save every… option
in the Time Steps Editor.
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New option for Truss type element, Include
Torsional Stiffness, is introduced to the Beam
Element Property dialog.
This option allows the user to explicitly
enable/disable torsional stiffness for truss elements.
When this option is disabled, the material property
entries for Poisson’s Ratio and Shear Modulus are
automatically disabled.
New/Updated Libraries
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File/Import STAAD-Pro file now has the option to import European data.
The following beam section libraries have been updated:
South African – Square Hollow Section
South African – Rectangular Hollow Section
AISC Rectangular and Square HSS
AISC Round HSS
AISC Single Angles
General Changes
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In the Results/Listings and Results/Peek, nodal displacement results X+DX, Y+DY, Z+DZ have been
renamed to X', Y', Z'.
In the Global/Load and Freedom Cases, the Apply Accelerations to options now also apply to the nodal
acceleration attributes. This means that the options are now also relevant even when Global Inertia Load is set
to None.
In the Results/Results Settings, a single Font setting is now applied to all results contours of the same
element type.
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Strand7 Release 2.4.2 for Release 2.4.1 Users
New API Functions and Changes
Please refer to the Strand7 R24 API Manual.pdf for more information.
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New API functions:
St7VectorTransformToUCS
St7VectorTransformToXYZ
St7GetModalResultsNFA
St7GetLinkType
St7UpdateElementPropertyData
St7SetHardeningType
St7GetHardeningType
St7SetTrussData
St7GetTrussData
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New API constant spStickingFrictionFactor for use when getting/setting the solver default values.
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Strand7 Release 2.4 for Release 2.3 Users
Strand7 Release 2.4 for Release 2.3 Users
Introduction
In addition to the completely new functionality in Strand7 Release 2.4, there are a number of changes that have also
been made compared to Strand7 Release 2.3. To avoid confusion for current users of Strand7, we present this list
of changes as a reference.
Menu Location Changes
The changes noted in this section relate to the relocation, name changes or significant changes to the way the
operation is performed in Release 2.4. The grouping of the changes is based on the menu location in Release 2.3.
File Menu
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Combinations
and Envelopes
File/Preferences, select the Results tab for
Combinations and Envelopes generation
Results/Options, select the Combinations or
Envelopes tab for generation settings
settings
Edit Menu
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Selection
Edit/Select
Select is now on the Strand7 main menu
Link Type
Edit/Link Type
Attributes/Link/Type
Select by
Property
Separator for Select by Property is “,”
Separator for Select by Property is “,” or “.”
depending on the regional settings in the
Windows setup.
Range for Select by Property is “-”
Range for Select by Property is “>”
View Menu
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Post
processing
Numbers
View/Options, select the Numbers tab for
Results/Options, select the Numbers tab for
post-processing number format
Attribute
Display
Attributes Display only has individual controls
post-processing number format
for showing/hiding attributes, values and as
resultant or component.
Attribute Display has Show all attributes,
Hide all attributes, Show all values, Hide all
values, All vectors as resultant and All
vectors as components as well as the
individual attribute controls.
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25
Strand7 Release 2.4 for Release 2.3 Users
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Snap Grid
Settings
View/Snap Grid
View/Snap Grid Settings
Attributes Menu
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Under Attributes/Node
Under Attributes/Node/Stiffness
•
•
•
•
Node Attributes:
Node Stiffness
Node Mass
Translational Stiffness
Rotational Stiffness
Translational
Rotational
Under Attributes/Node
Under Attributes/Node/Mass
•
•
Non-Structural Mass
Translational Mass
•
•
Non-Structural
Translational
•
Rotational Mass
•
Mass/Rotational
Beam Attributes:
Beam Pre
Tension
Attributes/Beam/Pre Tension
Attributes/Beam/Pre Load
Beam
Distributed
Force/Moment
Force: Under Attributes/Beam/Distributed
Force and moment: Under
Force
•
Principal
•
Global
Attributes/Beam/Distributed Load
•
Force Principal
•
Force Global
Moment: Attributes/Beam/Distributed
•
Moment Principal
Moment
Plate Attributes:
Plate Pre Stress
Plate Edge
Load
Plate Face
Load
Attributes/Plate/Pre Stress
Attributes/Plate/Pre Load
Under Attributes/Plate
Under Attributes/Plate/Edge Load
•
•
Edge Pressure
Edge Shear Stress
•
•
Pressure
Shear Stress
•
Edge Normal Shear Stress
•
Normal Shear Stress
Pressure: Under Attributes/Plate/Face
Pressure and Shear stress: Under
Pressure
•
Normal
•
Global
Attributes/Plate/Face Load
•
Normal Pressure
•
Global Pressure
Shear stress: Attributes/Plate/Face Shear
•
Shear Stress
Stress
Plate Elastic
Supports
Plate Heat
Transfer
Under Attributes/Plate
Under Attributes/Plate/Support
•
Edge Support
•
Edge
•
Face Support
•
Face
Edge heat transfer: Under Attributes/Plate
•
•
Convection
Radiation
Presented by Strand7 Pty Limited
Edge heat transfer and Flux: Under
Attributes/Plate/Edge Heat Transfer
Face heat transfer and Source: Under
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Strand7 Release 2.4 for Release 2.3 Users
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
•
Attributes/Plate/Face Heat Transfer
Heat Flux
Face heat transfer: Attributes/Plate/Heat
Both have the following options:
Source
•
•
Brick Pre Stress
Attributes/Brick/Pre Stress
Attributes/Brick/Pre Load
Brick Face
Load
Pressure: Under Attributes/Brick/Face
Pressure and Shear stress: Under
Pressure
Attributes/Brick/Face Load
•
•
•
•
Normal Pressure
Global Pressure
Shear stress: Attributes/Brick /Face Shear Stress
•
Shear Stress
Under Attributes/Brick
Under Attributes/Brick/Heat Transfer
•
•
•
Convection
Radiation
Heat Flux
•
•
•
Convection
Radiation
Flux
•
Heat Source
•
Source
Convection
Radiation
Brick Attributes:
Brick Heat
Transfer
Normal
Global
Vertex Attributes:
Vertex Stiffness
Vertex Mass
Under Attributes/Vertex
Under Attributes/Vertex/Stiffness/
•
Translational Stiffness
•
Translational
•
Rotational Stiffness
•
Rotational
Under Attributes/Vertex
Under Attributes/Vertex/Mass
•
•
Non-Structural Mass
Translational Mass
•
•
Non-Structural
Translational
•
Rotational Mass
•
Rotational
Edge Attributes:
Edge Heat
Transfer
Under Attributes/Edge
Under Attributes/Edge/Heat Transfer
•
•
Convection
Radiation
•
•
Convection
Radiation
•
Heat Flux
•
Flux
Face Attributes:
Face Heat
Transfer
Attributes/Face/Heat Source
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Attributes/Face/Heat Transfer/Heat Source
27
Strand7 Release 2.4 for Release 2.3 Users
Tools Menu
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Automatic
UCS
Tools/Geometry Tools/Create Surface UCS
Tools/Create Entity UCS
Move to
Global Origin
Tools/Move/to Origin
Tools/Reposition/to Origin
Flip Entities
Tools/Align/Flip Elements
Tools/Align/Flip Entities
Works on beams and plates
Works on beams, plates, faces, and load paths.
Tools/Convert/Merge Line of Beams
Tools/Merge/Line of Beams
Merge Beams
Works on beams, plates (creating a UCS on the
element local system) and analytic geometry
faces (plane, cone, sphere, torus)
It now also has an angle tolerance for extra
flexibility.
Merge
Element Pairs
Tools/Convert/Merge Element Pairs
Tools/Merge/Element Pairs
Intersect
Beams
Tools/Auto Intersect Beams
Tools/Intersect Beams
Tool Options
All available options were collected within one
dialog screen.
Tools/Options dialog has been refurbished with a
Under Copy, Move and Extrude: Each has the
following option
Under Copy, Move and Extrude: Each has the
following option
/by Projection/to Element Surface
/by Projection//to Entity Face
By Projection
to Entity Face
Tolerance can now be specified within the tool
dialog.
new look and new features. Various options
have been categorised under their specific tabs.
Geometry Face can now be referenced to be the
target face and Assign Selected is now part of
the Surface Definitions.
Property Menu
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Nonlinear
Material
Property dialog has Nonlinear material options
contained in Structural tab
Property dialog has Nonlinear tab
Cutoff Bar
Settings
Max Tension/Compression and Cutoff Type
set in Section tab of the Property dialog.
Max Tension/Compression and Cutoff Type
set in Nonlinear tab of the Property dialog.
Beam
Nonlinear tables set in the Structural tab of the
Nonlinear tables set in the Nonlinear tab of the
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Strand7 Release 2.4 for Release 2.3 Users
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Connection
Nonlinear
Property dialog.
Property dialog.
Beam –
Moment vs
Curvature
Moment vs Curvature and Axial Stress vs
Strain only available for beams
Set Moment vs Curvature for beams when
running nonlinear material if required instead
of fully coupled nonlinear beam
Beam
Geometry
Exact
Exact J
Exact J and SA
Calculates J of the beam cross section by
numerical methods
Calculates J, shear areas and shear centre of the
beam cross section by numerical methods
Soil Mass
Density
Soil Weight in the soil property dialog.
Soil (Bulk) Mass Density in the soil property
dialog under Material tab.
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Results to
Calculate
Select the Start tab in the solver dialog to
specify the results to Calculate
Select the Results tab in the solver dialog to
specify the results to Calculate
Linear Static
Load and
Freedom Cases
Specify Load cases to solve and only one
Freedom Case can be selected at a time from
Click Load Cases in the Linear Static solver
dialog Start tab to specify load and freedom
cases to solve for
Solver Menu
the dropdown menu in Linear Static solver
dialog Start tab
Contact Cutoff
Strain
In the solver dialog select the Defaults tab and
click Elements. Enter the Friction Cut-Off
Strain.
In the solver dialog select the Defaults tab and
click Nonlinear. Enter the Contact Cutoff
Strain.
Geometric
Stiffness (KG)
In the solver dialog select Include KG.
In the solver dialog select the Defaults tab and
click Nonlinear.
Finite Strain
Definition
In the solver dialog select the Defaults tab and
select Elements.
In the solver dialog select the Defaults tab and
click Nonlinear.
Linear
Transient
Dynamic
Solver
Method.
In the linear transient solver dialog select the
solution Method.
Defaults tab and select Dynamics.
Presented by Strand7 Pty Limited
In the linear transient solver dialog select the
29
Strand7 Release 2.4 for Release 2.3 Users
Results Menu
Operation
In the Strand7 Release 2.3
In the Strand7 Release 2.4
Graph Range
Bars
Error Bars under Graph Options
Renamed to Range Bars under Graph Options
Contour Node
Reaction
Under Quantity in Results Settings, choose
Reaction
Under Quantity in Results Settings, choose
Node Reaction
Heat Transfer
SRSS
Heat Transfer results given as RMS
Heat Transfer results given as SRSS (square
root of sum of squares)
User Contour
Limits
Separator
Separator for User Defined Contour Limits is
“,”
Separator for User Defined Contour Limits is
“,” or “.” depending on the regional settings in
the Windows setup.
Peek Beam
Strain
Under Beam Quantity select Strain/Curv.
Under Beam Quantity select Strain
Peek Tool
Slider
When using the peek tool to look at beam force
or moment diagrams, the location along the
beam is selected by moving the slider.
When using the peek tool to look at beam force
or moment diagrams, the location along the
beam is selected by clicking on the diagram.
Results Log
Viewer
The log file entries filter has to be relaunched
for every single change.
The log file entries filter is now an individual
dialog and allows multiple changes to be made
at a time.
Model Manipulation Changes
This section contains the changes made to existing tools used in model building or element manipulation.
Selection Tools
•
•
Vertices can be the Master when using Select Connected tool.
Selection of points can be via Node, Vertex or Snap Grid. This affects the following tools:
Copy by Direction,
Copy by Projection/to Line,
Copy by Projection/to Plane,
Copy by Project/to UCS,
Copy by Project/to Element Surface,
Move by Direction,
Move by Projection/to Line,
Move by Projection/to Plane,
Move by Project/to UCS,
Move by Project/to Element Surface,
Move by Skew,
Move to Origin,
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Strand7 Release 2.4 for Release 2.3 Users
Extrude by Direction,
Extrude by Projection/to Line,
Extrude by Projection/to Plane,
Extrude by Project/to UCS,
Extrude by Project to Element Surface,
Scale Nodes And Elements,
Scale By Taper,
Mirror.
Copy/Extrusion/Move Tools
•
•
•
Can extrude vertices to beams. Therefore, in addition to creating a plate or brick mesh with geometry, beam
elements can be created from vertices.
Can extrude brick faces to bricks (includes all the extrusion tools, even extrude by thickness). The Extrusion
tool now allows a brick element to be selected by faces, instead of selecting the whole element as in Release 2.3.
Copy, Extrude or Project "to surface" tools now have a new button to put the selected plates/brick faces into
the target list - so you can select to choose the target and then select to choose the source.
Auto-Intersect Beam Tool
•
•
Auto-Intersect Beams now Uses a Tolerance
Auto-Intersect Beams considers plate and brick edges - can intersect a beam with a plate or brick edge.
Other Changes
•
•
•
•
•
•
Convert Patch Loads to Beam Loads Tool: This tool now allows either all cases or selected cases to be
converted. This is helpful for examining only a portion of the patch load cases.
Merge Line of Beams tool now has angle tolerance.
Adjust Midside Nodes has an option "Curved/Straight".
Create Load Patches - there is a new angle tolerance. Previously adjacent loops of beams had to be perfectly coplanar before they would be considered to be flat so as to form a closed loop (4 or more edges). Now, if you
take lots of three consecutive edges at a time, treat these as a triangle, determine the normal and compare this
normal with the normal of the next adjacent triplet – if the normals are within the nominated tolerance, the
loop is considered to be "close enough" to co-planar
For Points and Lines tool, Move to UCS Average - for cylindrical system, the order of 2-3 determines position.
On the Tools Dialog, all the labels that denote (N)ode, (V)ertex or (G)rid, can now be changed by clicking
them
Geometry Changes
This section includes the changes made to geometry and automeshing in Release 2.4.
•
•
In the Geometry Clean Dialog, the options to "Duplicate faces" group have changed to the following.
Leave All Faces
Leave One Face
Delete All Faces
With the current options, it gives the user the flexibility between leaving multiple duplicate faces for solid
automeshing of enclosed volumes, or leaving only one face for surface automeshing of the structure.
When tet meshing and multiple parts are found, instead of the previous message box with the YES/NO
question, there is now a dialog box so that the user can choose the action to be taken.
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Strand7 Release 2.4 for Release 2.3 Users
Element Attribute Changes
This section includes the changes made to entity attributes in Release 2.4.
•
•
•
•
•
•
When a beam is split or subdivided, temperatures are interpolated where appropriate. This also applies to the
AutoIntersect Function.
Plate edge and brick face attributes are interpolated when graded.
Align Plate Axes Function now has two options; one is the alignment of local z axis with a reference. The other
is the addition of Tolerance angle between the local and target axes.
Node stiffness and damping, beam, plate and brick supports are now freedom case dependent. This now treats
these attributes similar to nodal restraint conditions.
The attribute dialogs can retrieve property number while joining (Ctrl+Click), which can then be assigned to
other elements. This useful when having multiple values and/or load cases.
When using Compression-Only element Supports, the state of the support (On/Off) is now monitored at the
nodes, not at the centroid of the face/edge of the element. It is therefore possible to model partial lift-off
situations, where a portion of nodes on an element is active, while the rest is inactive.
Element Behaviour Changes
This section includes the changes made on the ways the element and link types are handled in Release 2.4. This
includes the changes to Release 2.3 definitions, element property changes, and modification to attributes assigned to
the elements.
Beams
•
•
•
•
Truss elements now support torsion and sufficient restraints must be applied to avoid matrix singularity. To use
a truss without torsion, set J and/or G to zero.
The transverse shear stress distribution is now available for beam and plate elements. In addition to reporting
the highest shear stress across a section, the distribution is also available in the results.
Connection element may now be UCS dependent. The ends of a Connection element can now be assigned with
different UCS using Tools/Connection UCS to represent different connection conditions at the ends. The
same set of stiffness and/or material nonlinearity tables defined in the Connection property are used at both
ends, with the axes 1, 2 and 3 now aligning in the UCS instead of the global axes.
Pre-strain may be applied to contact elements to change the position of contact.
Plates
•
•
•
The Tri3 element has been improved in its bending behaviour as its formulation is completely new. Its
membrane and in-plane shear capabilities remain unchanged. The Tri3 elements now handle the drilling degree
of freedom similar to those higher order elements such as Tri6, Quad8, and Quad9.
The detection and suppression of possible singularities and drilling degrees of freedom has changed and the
Solver/Defaults/Drilling section now applies to Tri3, Tri6, Quad8, and Quad9 elements. Refer to the Strand7
help file for more information.
The calculation of transverse shear stress on plates (due to the transverse shear force) has now changed.
Previously the transverse shear stress was given as simply transverse shear force divided by plate thickness - this is
strictly the average shear stress. The true shear stress distribution is parabolic - it goes from zero at the +z,-z
surfaces to 1.5 times the average value at the mid-plane. Now when contouring transverse shear stress, the
correct distribution is used. This will also impact von Mises and Tresca stress since the transverse shear stress is
now included in that calculation. For the calculation of plate principal stresses (in-plane) the calculation is the
same as before (i.e. it ignores stresses not in the plane).
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Strand7 Release 2.4 for Release 2.3 Users
Links
•
Rigid links support a Cartesian UCS when they are designated as XY, YZ or ZX type. Tools/Auto
Assign/Restraints/Rigid Coonections also has a dropdown list to choose the UCS. This allows greater
flexibility in defining the restraint condition for a slanted surface.
Material Property and Model Changes
This section contains the changes made to properties other than that of the Beam, Plate and Brick types, as well as
the changes made to material models employed in Strand7. This includes the changes to the model definition, and
modified interpretation of constants.
General
•
•
Zero element property type is now allowed. This makes possible the insertion of null elements in the model file
to ensure that the element numbering does not change when the model is packed. Elements with zero property
type are now not packed.
Reorder property sets on Property Dialogs is now allowed, where the property numbers can be changed after
they have been created.
Laminate
•
•
•
The maximum number of plies in a laminate has increased from 100 to 300.
Laminate Properties are now referenced by a number and a name, e.g. “1: Laminate 1”.
Laminate results can be obtained at the ply +z and –z in addition to the previously available ply mid-plane.
Rubber
•
•
Brick property/rubber - label change - Mooney-Rivlin (G)
Rubber Coefficients Calculator, activated from the plate/brick rubber properties. This includes the addition of
the Poisson's ratio, which is used to calculate the rubber bulk modulus according to page 253 of the Theoretical
Manual. Also, when the interpolation produces curves with negative gradients, a warning becomes visible at the
bottom.
Soil
•
•
Duncan-chang materials are consistent with other soil materials in the way that in-situ data is applied.
All soil models now report the effective stress in results, with the pore pressure available separately (as either
total or excess).
Table Changes
This section includes the changes made to the tables in Strand7. Also covered in this section is changes related to
table assignment in Strand7, for example, in element property definition dialog and solver table definition. This
includes the changes to the handling of tables.
•
Thermal Expansion vs Temperature tables – can be instantaneous in addition to previous option (integrated).
This is related to the way the data is recorded. For the instantaneous option, the strain measurement is taken
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33
Strand7 Release 2.4 for Release 2.3 Users
against the reference temperature. Therefore each data point is the total strain of the material due to the
temperature change from the reference to current value.
For the integrated option, the strain measurement is taken as the incremental value between the two measured
temperatures. The total strain is therefore the sum of the area under the strain-temperature curve.
•
Some tables allow time units (Factor vs Time, Strain vs Time) – in conjunction with solver settings. For Factor
Vs Frequency Tables they also include the unit type, which is useful for scaling as well as in selection in solver
dialog.
Solver Changes
This section includes the changes made to the Strand7 solvers. This includes the changes to the solver calculations,
and solver default settings.
•
•
•
When geometry nonlinear results (GNL) are used as initial conditions in the natural frequency solver, the
deformed position is considered in drawing the mode shapes. The GNL position is regarded as the undeformed
configuration. It is possible to display the undeformed configuration similarly to Release 2.3 by changing a
setting via Results/Options/Other.
Solvers can now calculate Element Nodal Reaction Forces. This is especially useful in the debugging of models
with multiple nonlinearities, where force imbalance at nodes can be identified. It also offers a very powerful free
body diagram option on all or part of the mesh.
Solver Time Step Editor allows time units. This is used in conjunction with the creep models and other tables
with time components to simulate the time history of the model.
Data and Results Display Changes
This section includes the changes made to the way Strand7 handles result quantities, including differences in the
presentation of the numerical values.
Data Display
•
•
•
When the Dynamic Rotation is in Solid View Mode, if it's taking too long to draw and a new orientation is
required (i.e. the user moves the mouse before the drawing completes), then the present view is flushed
unfinished and drawing of the next frame is started. If you pause long enough, the whole picture comes up,
otherwise you get part drawings.
In both Online Editor and Results Listings, where previously there was a Right-Click item "Select
Highlighted", there is now also "Unselect Highlighted".
Contouring plate Discrete Thickness uses significant figures settings to group similar thicknesses into one
colour band.
Results Display
•
•
•
•
Attributes are shown for Load Case Combination results - all Load and Freedom cases included in the
combination are shown simultaneously.
Contour limits and ranges are stored separately for each result type, e.g. displacement, stress, etc. Also the user
can set either or both of Min/Max values.
The number of beam Slices can be set in the Peek tool.
In Beam Result Listings, Stress: Axial and Bending are now given in addition to Total Fibre stress. The stress
quantities "Max Shearing 1" and "Max Shearing 2" are now called "Transverse Shear 1" and "Transverse Shear
2" as now the full shear stress distribution is given (i.e. not just the maximum on the section).
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Strand7 Release 2.4 for Release 2.3 Users
•
•
•
•
•
•
•
•
For models with edge and face support, the support stress results can now be generated as Bearing Pressure in
the element local axis system.
The Graph tool can now plot in polar system and on a cutting plane. In addition, a tolerance can be set to
include nodes lying within the tolerance (but not on the specified line).
SRSS and CQC of combined results are supported (e.g. von Mises, Principal stress, etc), provided the Modal
Results are saved in the Spectral Response Solution.
When using Peek on Plates and Brick elements, the Gauss points are now highlighted when examining the
Gauss points values. In addition, the Peek tool can now list averaged and non-averaged node values (stress,
strain, etc.). For plate/shells elements, when the "Mid, -z, +z" buttons are visible, these buttons are now
additive (i.e. more than one can be down at one time), whereas previously they were exclusive.
When results are open, the Entity inspector now lists attributes. All post processing now shows the actual loads
and attributes applied for that particular load case, increment, time step, etc. This is the load that takes into
account the factors (if applicable) and is also visible in the Entity Inspector.
The Hide Zeros option is also available in the Results Listings (right-click the spreadsheet).
In Results Listings, when in Multi-Case mode and there are many load cases, it is now possible to Shift-Click in
order to apply the same selection to a range of load cases. Previously if you wanted to turn off consecutive load
cases you had to do them one by one.
In previous releases, the option to calculate the element node force was not available, i.e. only the node reaction
was available, which is equivalent to then element node force when the contribution from all elements at a node
is taken into account). In Release 2.4 we have the option to calculate what is effectively the free body diagram
(FBD) of each individual element. Furthermore, we can also calculate the FBD of groups of elements by
summing the nodal contribution of each element to the group of elements. Until now, these nodal forces and
moments were only obtainable by drawing the vector of Element Node Force. They are now available in the
Peeker. Firstly, there is a change to the Node page - "Reaction" has been renamed "Reaction (Nod)" and the
new item "Reaction (Elt)" has been added. Reaction (Nod) is the same quantity as the previous Reaction
quantity. Reaction (Nod) gives the sum of the reactions of the visible elements at the selected node. This
option is only available when the display is set to vector of Element Node Force. In addition, the Reaction Sum
page also allows the selection of either Node Reaction or Element Reaction. Node Reaction is as before.
Element Reaction sums the node forces and moments based on the elements that are drawn. Similarly to
Reaction (Nod), this option is only available when the display is set to vector of Element Node Force.
Animation
•
Create Animation - the dialog box that allows you to select the cases to include in the animation has a rightclick menu that can be used to set every 2, 3, ..., 10 items. This is useful for long lists. In addition, this dialog
responds to shift-click to set a range of entries.
File Import/Export and Save/Load Changes
This section includes the changes made to the file import/export options of Strand7. This does not include the new
formats available in Release 2.4. Rather it contains the difference in the handling of existing file formats that are
supported by Strand7, as well as Save Submodel feature.
•
•
•
When a linear static submodel is created, each freedom case is automatically associated with the appropriate load
case in the Load Case table.
The results file name will now be based on the current model name by default, renaming the St7 Model File
outside Strand7 will update the results file names and paths for future solutions. Similar to File/Save To
operation, but the model will remember the previous results file names and paths.
File/Open can now open multiple Strand7 files at once. Also, the maximum number of files simultaneously
open is now 10.
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Strand7 Release 2.4 for Release 2.3 Users
General Changes
This section includes all important changes that do not fall into the above categories.
•
•
•
•
•
The following operations are now included in the Undo list.
Creation or deletion of load and freedom cases from the Global Load and Freedom Cases dialog.
Changes to, creation and deletion of Global/Coordinate Systems (UCS).
Creation/Deletion of Load/Freedom cases.
Units changes.
For the Groups dialog, +/- expands and contracts the list of subgroups, while single-click click the cube to
toggle the entity On/Off state. In addition, this dialog has Select All, Unselect All, Toggle All buttons.
The Solver tab under File/Preferences is no longer available. A single solver executable is now shipped.
BXS Generator now accepts Links in the mesh. Use Links to provide shear compatibility between independent
parts of a cross-section (e.g. mirrored sections - use links to generate a J that twists both sections as one, instead
of just twice the J of one section).
Click on the Model Window Status bar to activate some shortcuts (e.g. units, angle, displacement scale, default
group).
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What’s New in Strand7 Release 2.4
What’s New in Strand7 Release 2.4
New Import/Export Options
NASTRAN Entity Numbers
NASTRAN entity numbers are assigned to the new Strand7 attribute type Entity ID when a NASTRAN file is
imported.
NASTRAN Import/Export RBE
The NASTRAN RBE cards are now supported and imported/exported via the new Multi-Point Link in Strand7.
NASTRAN Import/Export CELAS
NASTRAN CELAS elements are now translated via Strand7 beam connection elements. They can be zero or finite
length.
NASTRAN Export PCOMPZ0
The NASTRAN PCOMPZ0 parameter is now supported. This defines the distance from the reference plane to the
bottom surface of a layered composite property.
NASTRAN Export Unused Properties
An option is available to select whether unused properties are to be exported to a NASTRAN file. This can be used
to avoid a NASTRAN error message when trying to solve a model that contains unreferenced property data.
NASTRAN Export Reference Temperature Case
This option is used to select the load case from which its temperature attributes are to be exported as a reference
temperature case.
STAAD Groups
STAAD Groups are supported when a STAAD file is imported. For elements that are assigned to multiple groups in
STAAD, Strand7 assigns them to the last group in which they appear. Whenever STAAD nodes include group
names that are numeric they are assigned to the Strand7 Entity ID attribute for the node.
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What’s New in Strand7 Release 2.4
STAAD Section Database
Specified databases can be searched
when importing a STAAD file into
Strand7 to find the relevant section
details. This allows you to create your
own beam section library in Strand7, or
choose an existing library, which will
be searched for the STAAD section.
This is in addition to the standard
country databases (Australian, British
and American) that Strand7 provides.
SAP2000 Import
SAP2000 files (*.s2k) can now be imported into Strand7.
Binary STL Import/Export
Binary Stereo-lithography files (*.stl and *.stb) are now directly importable into Strand7. Strand7 files can also be
exported as an *.stl or *.stb file. In this case beams as solid, plates and brick free faces are exported. A default
property number can be set for the imported plates.
ACIS Group Import
The ACIS (*.sat) importer assigns ACIS solids to groups.
STEP Import
STEP files (*.stp and *.step) are becoming increasingly popular for the transfer of geometry data between
CAD/CAM packages. Strand7 can now import these files extracting geometry information for meshing, similar to
the previously available IGES import option.
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What’s New in Strand7 Release 2.4
ANSYS Import/Export
Strand7 R2.4 imports and exports ANSYS
files (*.dat and *.cdb). This provides
another method of file transfer to and from
other packages.
IGES and STEP Export
It is now possible to export geometry
information from Strand7 in both IGES
(*.igs and .iges) and STEP (*.stp and
*.step) formats.
Changes made to geometry within
Strand7, i.e. cleaning, splitting, zipping,
etc., will be included when exporting.
DXF Import Circle Settings
The DXF import dialog allows for control of the number of beams that are used to
model circles or part thereof. A specific number of segments per circle can be set or
alternatively an arc length for each beam can be entered.
DXF Export Plate as Solid
Plates can be exported as surfaces or solids during DXF export, similarly to the previously available option for
exporting beam elements as solids or sections.
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What’s New in Strand7 Release 2.4
Image Export Reset
If the Image Width or Image Height is changed when exporting a bitmap or jpeg image, Reset can be used to
change the resolution back to the current model window dimensions.
New Units Features
Calorie Energy Unit
The Calorie unit is available for energy. 1 cal = 4.1868 Joules.
KSI Stress Unit
The ksi stress unit is available.
User-Defined Units
Under File/Preferences you can now set User defined units to be used every time a new model file is opened.
This option offers the flexibility of selecting any combination of units as the defaults, in addition to the previously
available standard sets (SI, Nmm, IPS, FPS, etc.).
Time Units
Time units can be selected in two different sections of Strand7.
In tables that are Vs Time, units of seconds, minutes, hours or
days can be selected. In the Transient and Quasi-static solvers,
units of milliseconds, seconds, minutes, hours or days can be
selected in the time step editor. These provide greater
flexibility for creep analyses in particular.
Anisotropic Plate/Brick and User-Defined Beam Units
Anisotropic plate and bricks and user-defined beam element properties contain units information, consistent with
the model units, for each parameter. This facilitates the definition of these parameters, the understanding of how
they are used in the solver, and also allows them to be properly scaled whenever the units of the model are changed.
Unit Scaling
When units are changed within Strand7 and the option to scale the model is selected, everything in the model is
now scaled. This includes tables, anisotropic plates and bricks and user–defined beams.
Undo Units
Changes to the units used in a model, including units scaling, can now be reversed using the undo function.
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What’s New in Strand7 Release 2.4
New Display Options
Background Image
Would you like to add a company
logo to the background of all your
model and results contour plots? You
now have the ability to include a
background image in the Strand7
model window.
Choose View/Options and select the
jpg or bmp image you require. The
image will be displayed in the model
window while the model can be
rotated and viewed as usual.
Plate/Brick Connection Free Edge
Free Edge settings can be made such that if a plate edge is correctly
connected to a brick edge it will not be displayed as a plate free edge.
Ignore Cavity Loop
Under View/Options, cavity loops can be ignored when
looking at face free edges and face t-junctions. This will
make it easier to identify free edges that are not intentional
in a model.
Solid View Dynamic Rotation
Dynamic rotation of large models in solid view can often be slow. Now if the drawing has not completed and a new
orientation is required, e.g. you have used the mouse to rotate the model to a new angle, then the present view is
flushed unfinished as per a wireframe view and drawing of the next frame is started.
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What’s New in Strand7 Release 2.4
Rounded Contour Limits
The performance of the Rounded option for
automatically displaying tidy contour legends that show
rounded whole numbers has been improved. This can
make it easier to compare values during quick checks.
Contour Beams
Like the previously available plate and brick
contours in the Entity Display, beam elements
can be contoured for a variety of options,
including length, applied attributes, etc. It is also
possible to create a user defined contour which
can be based on node or beam end values.
Soil Fluid Level Contour
For plate and brick elements, the fluid level in the soil material can be contoured. The option is in the Entity
Display.
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What’s New in Strand7 Release 2.4
Move to Offset
When plates and beams are offset you can choose
to draw them in their offset position or directly
attached to their nodes (as if the offset is zero).
It can sometimes be useful during construction of
large models to draw the plates and/or beams
without the offset shown.
Zero Length Beams and Links
When a zero length master-slave link or beam element is created they will still
be seen in the model window. For link elements the cross at the end of the
link will be drawn, for beam elements a small dot will be drawn. This makes it
easier to identify and select the beams or links if required.
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What’s New in Strand7 Release 2.4
New Selection Options
Free Edges/Ends Selection
The option is now available to select elements with free ends (beams or links) or
free edges (plates or bricks), if required, when free ends/edges are shown. This
will be of benefit in large and complex models where small free edges can be
difficult to track down. This preference is set in View/Options.
Select Entities on Load Path
When a load path (see Moving Load) is defined in a model it is
possible to select all nodes and/or elements that lie on this load
path by using Select/Entities on Load Path. This dialog allows
you to choose from All Load Paths, Selected Load Paths and
Unselected Load Paths.
Select by ID
Nodes and elements can be selected by their Entity ID attribute, if they have one defined.
Select Plate Faces
Plates that lie within a certain angle tolerance to a
master plate can be selected via Select/Plate Faces.
This is useful for plate surfaces that do not lie in a
specific coordinate system.
If Toggle Node Select is active, the nodes attached to
the selected plates will also be selected.
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What’s New in Strand7 Release 2.4
Select Brick Faces
A selection option has been added to allow for the easy selection of
individual brick faces when they do not lie in one of the coordinate
systems: Select/Brick Faces. The face of a brick needs to be
selected as the master element and then all faces that lie within the
angle tolerance of that element will be selected.
If Toggle Node Select is active, the nodes attached to the selected
bricks will also be selected.
Vertices in Select Connected
Vertices can be selected as the Master element when selecting either vertices or faces in Select Connected.
Select Beams on Patch Plates
Choose Select/Beams on Patch Plates to select only those beams in a model that
lie on a load patch element.
Select/Unselect Highlighted from Spreadsheet
Select and unselect the elements in the model belonging to the highlighted cells in the spreadsheets such as Online
Editor and Results Listings is now possible.
New Load and Freedom Case Options
Freedom Case Dependent Node Stiffness/Damping and Element Supports
Nodal stiffness, damping and elastic supports are now freedom case dependent.
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What’s New in Strand7 Release 2.4
New Link Types
Multi-Point Link
The multi-point link is a new link that can be used to define a multi point
constraint equation between any number of node/degree of freedom
combinations. A typical use is for distributing loads to a number of nodes
without affecting the stiffness of the structure.
The multi-point link allows any number of nodes to be connected to a single
Slave node.
If the User specified option is selected then arbitrary relationships between each
of the nodes and degrees of freedom may be defined; e.g. equations of the form
1.3DX(3) = 2.1DX(4) – 0.9DX(6) + 2.3DX(12) + 1.53 can be defined.
This link is compatible with NASTRAN and ANSYS MPCs when importing
and/or exporting.
The multi-point link can be edited in Edit/Multi-Point Link.
The Interpolated option couples the linked nodes and the slave node such that
the motion (translations and rotations) of the slave node is interpolated and
averaged without contributing additional stiffness to the linkage. One common
use of the Interpolated type Multi-Point Link is to transfer point forces and
moments from the slave node to the linked nodes with no additional stiffness
enforced in the linkage, unlike Rigid connections where the linkage is assumed to
be rigidly stiff. Tools/Auto Assign/Restraints/Multi-Point Link can be used to
quickly establish the link. The following is an example where a cylinder buckles
due to the applied load at the multi-point link:
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What’s New in Strand7 Release 2.4
Attachment Link
The attachment link is a new link that is very useful for connecting incompatible meshes such as assemblies meshed
from imported CAD geometry. It allows a node to be linked to a particular location on an element face or edge and
the multi point equations to enforce that relationship are automatically generated at solve time.
The attachment link can be created in the same way as existing links. The
connection can be for Translations, Rotations or Both and is connected from a
node to a specific u-v location on a face (or along a beam).
While it is possible to manually create the attachment link, an automatic process can be
used to connect large areas together. This is a two step process.
The first step is to assign the attachment attribute to the areas that are to be
connected. The attachment attribute can be assigned to beams, plates, bricks and
geometry faces.
Once all the attachment attributes have been assigned use Tools/Attach Parts to
automatically create the attachment links where they are required.
The model below shows a typical application of this procedure where an incompatible mesh has been made
compatible by the use of the attachment attribute applied to the edge of plate elements. This forces the two parts to
remain connected or attached, as shown in the figure on the right.
Another example is two intersecting plates where the mesh is not compatible. The attachment link is not restricted
to edge-edge or face-face connections, but can be used in an edge-face situation similar to the figure shown below.
Here it is easy to see that the overall displacement of the incompatible mesh (left) is comparable to the compatible
mesh (right) due to the attachment links.
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What’s New in Strand7 Release 2.4
The attachment link and attachment attributes can be used for all element types in Strand7, including beams, bricks
and geometry. This means you can attach beams to plate meshes without worrying about nodes in the correct
location, or even beams to other beams without splitting them.
The connection is not restricted to meshes that have no gap between them. A specified Max Gap can be entered at
the attribute level to allow parts of a model to be connected that are separated in some way. A particularly useful
feature is the use of the Flexible attachment, which will create beams across the gap instead of rigid links (Rigid
attachment). Using a beam connection allows you to specify these as point contacts and model a contact situation
with dissimilar meshes, as shown in the figures below.
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What’s New in Strand7 Release 2.4
Automatically
created beam
elements with
attachment links
at one end
The attachment link can also be particularly
useful for automeshed assemblies. The figure
below shows an assembly of a base, two lugs and
a rod. Clearly the lugs are not compatible with
the base of the structure as the mesh density is
finer, however by using the attachment link
these sections can be connected so that they act
as fully welded under load. You will then find a
continuous displacement plot similar to the
figure on the right.
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What’s New in Strand7 Release 2.4
New Element Tools
Move by Skew
Tools/Move/by Skew allows elements in a model to be skewed.
The selected elements can be skewed in any or all of the three
global directions from an origin point.
The example on the right shows a rectangular mesh of plate
elements that have had there global X axis skewed by 10 degrees
in the Y direction. The origin point is the reference point that
remains fixed during the skew operation.
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What’s New in Strand7 Release 2.4
Scale by Taper
Tools/Scale Nodes and Elements/by Taper allows a model to
be scaled about a specific axis. A line is specified in the model
and the selected elements can be scaled about this line in any of
the three global or Cartesian UCS axis directions. A taper ratio,
using P1 and P2, can be assigned to create a tapered section of
the model.
The example on the right takes a rectangular plate mesh and
tapers the vertical dimension about the horizontal centre line.
The right hand end is scaled to 50% of the original height.
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What’s New in Strand7 Release 2.4
Cut Beams and Plates
Beams and plates can be cut and the nodes automatically adjusted by a user-defined line. The cut line can be
defined by a straight line, a cutting plane or a UCS.
If required, beam elements can also be automatically created along the cut line. These beams could be extruded
normal to the plate to create stiffeners, etc.
New Grade Plates and Bricks
Two new grade tools have been developed:
The first is Quad Grade Tri
Circle Grade
and the second is Full Quarter
.
Extrude Vertices to Beams
Vertices can be selected in a model and extruded to beam elements in the same way as nodes can be extruded to
beams.
Extrude Brick Faces
To extrude a brick element on top of an already existing brick element, the extrusion tool can now be used directly
on the brick face. Previously plate elements were needed. When the extrude tool dialog is open you will be able to
select individual faces of the brick to extrude into connected bricks.
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What’s New in Strand7 Release 2.4
By Projection Normal to Surface
When using one of the projection
tools, e.g. Extrude/by Projection/
to Entity Face, Copy/by
Projection/to Plane, etc., the
direction can now also be specified
as Normal to the Plate Source.
The direction is defined as the
average normal of the plate in the
local +z direction.
This is particularly useful when the
projection distance is of a variable
thickness.
The lower plate mesh was
extruded into bricks (red) by
projecting to the upper plate
mesh (blue)
By Projection to Surface Selection
When using Tools/Move, Copy or Extrude/by Projection/to Entity Face the surface can be defined by selecting a
number of plates or bricks and using Assign Selected.
By Projection to Geometry Face
It is now possible to also use geometry faces as reference when using Tools/Move, Copy or Extrude/by
Projection/to Entity Face.
Create Entity UCS
A UCS can be automatically created on any selected beam, plate, geometry face or load path.
Detach Elements
When it is required that sections of a model be detached but the nodes remain coincident Tools/Detach Elements
can be used. This tool allows you to select any number of elements and detach them from the mesh without
physically moving the nodes apart. The nodes will be coincident and if required master-slave links or beams can be
placed between them. The master-slave links can be zero length as can the beam elements, as long as they are
defined as a connection element.
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What’s New in Strand7 Release 2.4
Auto Intersect Beams with Plates and Bricks
The Auto Intersect Beams tool can now to be used in conjunction with plates and
bricks. If a single beam element intersects plate or brick edges, the intersection point
will be found and the beam subdivided accordingly. In addition, the intersection
tolerance is now the element zip tolerance, therefore intersections do not have to be
exact.
The auto intersect tool now also includes a Max Gap and Min Angle setting.
Max Gap: This controls the maximum gap allowed between beams and/or plates to
when intersecting them.
Min Angle: If the angle between the beams and/or plates is less than the Min Angle
they will not be intersected.
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What’s New in Strand7 Release 2.4
Extrude Along a Line
A new extrusion option is available in Strand7 R2.4,
Tools/Extrude/by Line. This allows you to define a line of
beams in any shape and then extrude elements along this line.
Rotate Plates
Plate element connections can be rotated to easily change the node order on the element. This effectively rotates
the local axes directions without using the local axis angle attribute and is particularly useful for aligning the A-B
directions on a plate for subdividing.
Adjust Mid Side Nodes
Midside nodes can be adjusted according to a straight or curved edge.
Reposition to UCS Plane
Tools/Reposition/to UCS Plane allows you to realign a model so that it is aligned
with a particular plane in either the Global or a UCS system.
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What’s New in Strand7 Release 2.4
Extrude to Point
By choosing Tools/Extrude/by Projection/to Point, vertices, nodes, beams and
plates can be extruded to a single point in space.
If a beam is extruded a triangular plate is produced.
If a triangular element is extruded, a tet element is produced.
If a quad element is extruded a pyramid element is produced.
Align Beams to Plates
A new alignment tool exists that allows a beam’s Principal 1 or 2, or Local x or y axis to be aligned with the attached
plate element normal. This is particularly useful for modelling scenarios where you wish to align beam stiffener
elements with a plate skin.
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What’s New in Strand7 Release 2.4
Mesh Clean
The new location of nodes after a mesh clean can be controlled by the user.
Under the Options tab, when a mesh is cleaned you can choose to
maintain the coordinates of the higher or lower node number, zip the
nodes and place them at the average coordinate or keep the coordinate of
the selected node.
The setting Keep Lower node/Keep Higher node/Accumulate controls
which attributes are to be kept.
The Zip tab allows you to specify whether to Allow zero length links and
Allow zero length beams.
Create Load Patch Tolerance
A tolerance to control whether a load patch is automatically created has been
introduced. The normal of three consecutive edges is compared to the normal of an
adjacent set of three consecutive edges and if the angle between them is within the
specified tolerance (between 0 and 30 degrees) they are considered co-planar and a
load patch is created.
Patch Loads to Beam Loads Check
The convert patch loads to beam loads tool now has a check only option. This option
checks that all edges of patch plates have beams associated with them. If an edge does
not have a beam then this edge remains selected. This will ensure load is not
accidentally lost due to missing beams.
Edges will also stay selected if the tool is used in its full capacity and finds missing
beams along patch plate edges.
If the solver is launched using patch plates and there are missing beams a warning is
issued and the option to cancel the solve and correct the problem is given.
If duplicate beams are found on an edge, only one of the beams will carry any patch
plate load.
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What’s New in Strand7 Release 2.4
Undefined Beam Section Offset
When a beam element has an undefined section, Tools/Auto Assign/Beam Offset
can still be used to offset the beam to the centroid or shear centre.
BXS Geometric Centre Offset
The BXS offset now has an extra option to offset to the geometric centre of the section, i.e. the centre of the
bounding box which contains the section. This is achieved through Tools/Auto Assign/Beam Offsets.
Copy, Move, Extrude by Plate
Thickness
This is useful to copy, move, or extrude by
thickness when the plate mesh has variable
thicknesses. The Use plate thickness
option is included in
Tools/Copy,Move,Extrude/by Thickness.
Tessellate Lines at T-Junctions
A new option Include T-Junctions is available in the Tools/Tessellate Lines to create a line at the T-junction.
Auto Adjust Mid-side Nodes
A new option Auto Adjust Mid-side Nodes is available in the Tools/Options/Subdivide. If set, the subdivision
operation will reset the position of the mid-side nodes of the elements to be half-way between the corner nodes.
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What’s New in Strand7 Release 2.4
New Geometry Tools
Intersect Edges
Edges can be selected and the intersection between them found. A vertex is placed at each intersection detected
during the operation. If Split Intersected faces is set, when two shared vertices are detected, the underlying face
is split according to these vertices. The Distance tolerance is used to determine valid intersections. This tool can
make manipulation and preparation of geometry for automeshing easier, especially when used in conjunction with
Graft Edges to Faces and Split Face by Vertices.
Split Face by Vertices
Split lines can be created within Strand7 instead of just at the CAD stage. A line can be drawn between two vertices
on a face and the face will be split along a line that follows the parametric space of the face between the two vertices;
e.g. on a plane you always get a straight line, but on a cylinder you may get a straight line, an elliptical or a helical
line, and on a spline surface the line will depend on the shape and definition of the surface. This is an ideal function
for creating node lines in specific areas.
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What’s New in Strand7 Release 2.4
Split Face by Plane
Split lines can also be created in Strand7 by
using Split Face by Plane. Faces can be split
according to a plane defined in the global axis
system or a Cartesian UCS.
Split Face by Plane also includes a Create Cut
Faces option. When this is set, planar faces are
automatically generated on the cut planes.
Either 1 or 2 faces can be generated, with 2
faces being required if two separate solids are to
be modelled.
Graft Edges to Faces
The graft tool has been enhanced so
that it will now graft all edge types
with all face types (previously only
straight lines on planes could be
grafted). Graft one face onto another
face to ensure that after surface
meshing there is a compatible node
line between the two.
Incompatible mesh
when not grafted
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Compatible mesh
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60
What’s New in Strand7 Release 2.4
Morph Edges
The Morph Edges tool can be used to close gaps between faces. In the
example on the right a triangular face is removed from the geometry leaving
a gap between two edges. Using the morph tool, the two free edges can be
morphed together to close the gap. While this function is always performed
in the background during a geometry clean, the functionality is also available
as a tool.
Rebuild Faces
Users sometimes import geometric faces that have poor underlying B-spline surface definitions. While the
geometric shape of the face may seem to be appropriate, due to poor surface definitions automatic surface meshing
of the face may lead to extremely poor mesh quality that is inappropriate for finite element analysis. With the new
option of Tools/Geometry Tools/Rebuild Faces you have the option of refitting a new better quality surface over
the existing surface. This new surface definition allows for a better quality automatic surface mesh.
Original geometry and resulting automesh
Rebuilt geometry and resulting automesh
As part of this rebuild feature it is possible to view the control points of the surface, via Entity Display, to gain an
understanding of the surface definition and the degree and number of control points required to generate a better
mesh.
Create Vertex by Projection
A new vertex can be created based on an existing node, grid point or vertex in the model. Select the edge to create
the vertex on, then ctrl-click a node, grid point or vertex. If the clicked point can be projected in one of the three
Cartesian axis directions, then the newly created vertex will be at the projected position on the edge. Repeated ctrlclicks will cycle the projection in the X, Y and Z directions.
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What’s New in Strand7 Release 2.4
Coincident Faces
When planning to perform a contact analysis or solid mesh an assembly it is important to ensure that the mesh of
coincident faces is compatible. When performing a geometry clean, if Strand7 R2.4 finds two coincident faces, one
of these faces will be deleted and the remaining face will be copied to create the second face. This ensures that the
automesh generated is identical for the two faces.
Skip Edge Transitioning
Skip Edge Transitioning can be set in the surface
Edge transitioning
automeshing dialog. When this is set the mesh along
the edge of a face will not transition from the smallest
element to the largest element but will instead
maintain approximately the same edge length. This is
useful if a specific distance between each node on the
edge is required.
No edge transitioning
Show Normals
In the same way that the orientation,
or normals, of a plate can be shown,
they can now also be shown for
geometry faces. Showing the normals
of the geometry face allows you to
determine the orientation of the plates
that will be present after automeshing.
The size of the normals is adjustable.
By using Tools/Align/Flip Entities
you can change the direction of the
normals on the geometry if required.
Show Control Points
The control points for NURBS can now be shown. This can be useful for diagnosing faces that do not generate
ideal meshes.
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What’s New in Strand7 Release 2.4
Face from Cavity
Tools/Geometry Tools/Face from Cavity
allows a face to be created based on a selected
cavity in the model.
Convert to Nurbs
Tools/Geometry Tools/Convert to NURBS allows you to convert analytical surface to NURBS surfaces. This can be
useful if the geometry definition of the analytical surface produces a poor mesh. You can convert the surface to
NURBS to obtain an improved automesh.
Geometry Cleaning
The Minimum Feature Length is set in the geometry clean dialog. This controls how small and edge or gap should
be before it is cleaned out. Separate to this is the Geometry Accuracy setting given in the Tools/Options and as
Distance in Graft Edges to Faces and Intersect Edges. This setting controls how accurate the morphed edges,
grafted edges, etc must be in the rebuilt geometry. It is important that the Geometry Accuracy is the same or
smaller than the Minimum Feature Length.
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What’s New in Strand7 Release 2.4
Convert Plates to Faces
Geometry can be created from a plate mesh by using
Tools/Convert/Face from Plate. Any plate element can be
turned into a geometry face and from this an automesh can
be generated or the geometry exported as an IGES or STEP
file.
Using this feature will allow for a rough hand mesh to be
generated before a more refined automesh is carried out.
If the original plate mesh is not compatible before
converting it to faces, the geometry tools, i.e. Graft Edges
to Faces, Split Face by Vertices, etc., can be used to repair
these incompatibilities before automeshing.
Face from Beam Polygon
Geometry can be created in
Strand7 based on planar beam
elements. A closed loop of beam
elements can be selected and with
Tools/Geometry Tools/Face from
Beam Polygon, this can be turned
into one or more planar faces,
depending on any cavity loops that
exist.
A target face can be chosen such
that the generated face is then
projected onto the surface of the
target face.
Check initial self-intersections in Tet meshing
This option is set in the solid automeshing dialog. When it is set, the surface mesh will be checked for selfintersecting elements. It can help to find invalid surface meshes before attempting to tet mesh.
Delete Cavity Loops
All the cavity loops within a face can easily be removed at once by using this tool via Tools/Geometry Tools/Delete
Cavity Loops.
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What’s New in Strand7 Release 2.4
New Design Modules
Concrete Reinforcement
Concrete reinforcement checking is now part of Strand7. In this release, reinforcement can be modelled on
plate/shell elements and moments and reinforcing evaluated in the results.
Choose Property/Plate RC to activate the concrete reinforcement dialog, which allows you to specify the concrete
reinforcement lay up. This includes bar diameters, spacing, etc.
The concrete and steel properties, including yield stresses are specified and are used according to standard concrete
reinforcement calculations.
A major advantage to using Strand7’s concrete reinforcement analysis tools is the ability to specify whether the
analysis is a simple bending problem or whether membrane forces should also be included as part of the calculations.
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What’s New in Strand7 Release 2.4
Different reinforcement layouts can be assigned to
different plates in a model and skew reinforcement
may be specified by defining the angle between
reinforcement layers.
The plate concrete reinforcement does not have to be specified prior to solving; similarly to linear load
combinations, all calculations for reinforcement are performed by the post-processor. Concrete reinforcement
results can be assessed in any result file that calculates forces and moments.
A specific contour type for concrete
reinforcement exists for plate/shells.
Wood-Armer Moments can also be
calculated and contoured.
Values of the total area of steel required
per unit width of concrete, or the bar
spacing required for a specific bar size can
be contoured on a layer-by-layer basis.
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What’s New in Strand7 Release 2.4
Construction Sequence
Strand7 R2.4 now includes the ability to complete a staged construction sequence analysis. This allows you to
control the elements that are active during each stage of the analysis – elements can be activated and deactivated at
any stage.
There are numerous examples of construction sequence analyses including modelling the construction of a high-rise
building where the first floor is built and is subject to gravity before the second floor is built and so on. Another
example is modelling the construction of a cable stay bridge where the deck is built and supported by temporary
towers before the cables are installed and prestressed to provide the actual deck support.
Construction sequence analysis is not limited to adding components but can also be used for excavation type
situations. In the example shown below a tunnel is being excavated from soil, and as each layer is excavated a
concrete liner is added. This is a staged construction sequence because the soil is only removed in small sections
before a liner is added and at all stages gravity is acting on the model.
Step 1: No soil removed
Step 6: Half the soil removed and
some concrete liner installed
Step 13: All the soil removed and the
complete concrete liner installed
Stages are defined using groups; therefore groups should be defined based on the sections of the structure that are
active at the same time. For example you may create groups like Soil Layer 1, Soil Layer 2, Concrete Liner 1, etc.,
as each of these is removed or included at separate stages of the analysis. Once groups are defined, the specific
stages of the analysis can also be defined.
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Choose Global/Stages to define each of the
stages of the construction sequence. For each
stage created the inactive groups need to be
specified.
If your groups are defined in a way similar to the
actual sequence of construction (or excavation)
you can choose to automatically create
stages in the model based on your group
hierarchy.
the
Once your stages are defined you can create an animation
as a preview before solving. The animation steps
through the stages created. This allows you to easily determine at what stage different components are being added
or removed from the model and offers a good visual checking tool. Alternatively to view a single stage, double click
the stage name and the elements included in that stage will be drawn.
During the construction sequence nodes can be morphed into position. With this option, when elements are first
added they will be morphed (deformed) to take the shape of the space they are intended to occupy, irrespective of
the shape the elements were initially. This morphed shape is then considered to be the stress-free state of the
elements. If the morphing option is not set, then when the elements are added to a stage, their initial stress-free
shape is their original shape. As part of this you can choose to Move fixed nodes. With this set when new sections
are added, even the fixed nodes can be moved to a new location to accommodate the morphing. If Rotate Clusters
is set, Strand7 will include rotational displacements when joining the new components to the existing structure.
Care should be taken when using this to ensure this is required for your model.
When the model is completely built and all the stages of the sequence are defined it can be solved using the
Nonlinear Static solver. Nonlinear load increments can be set up as per previous releases of Strand7 by running an
unstaged analysis
, however a staged analysis
requires additional incrementation information. Here you
have the ability to apply loads to each of the stages. Not all stages need to be solved; you can select the stages to be
solved and the load factors to apply to them.
In the example below, gravity is the only load on the structure at each of the stages while the soil is removed and the
concrete lining installed. Once the tunnel is completed the final loading sequence consisting of a pressure load
acting on the top surface of the soil is then included.
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If there are a number of stages in your model then it
may be easier to automatically set up your load
increment table
.
This tool allows you to specify which stages are
included and what the initial and final load factor
should be for each of these.
While the actual process of the construction sequence can only be solved using the Nonlinear Static solver, any of
the other solvers allow you to solve for specific stages of the model. For example, if you wish to find the total
displacement of a structure under gravity after the first stage then you can select this stage as the Active Stage in the
Linear Static solver dialog. Effectively this offers a convenient way to exclude elements from an analysis, even if they
remain in the model.
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When analysing the results the same method is used as for unstaged nonlinear static analysis. Each increment is
given in the result case dropdown with the corresponding active stage also shown. Results can be interrogated as
usual however only active elements will have results. The display of inactive elements is controlled via
Results/Options.
If the Morph option is used, then the element (Beam/Plate/Brick) displacement contours can either be set to
Relative to Birth Stage or Relative to Initial Positions via Results/Options. The morphed positions, i.e. the
Birth Stage coordinates are also reported in the Results/Listings.
Moving Load
Strand7 R2.4 offers automatic tools that can be used for moving load analysis.
•
Load Influence Solver
The basis of the moving load module in Strand7 is the Load Influence solver. This new solver is used to determine
influence lines and influence surfaces. In other words, you can determine the effect that a unit load (force or
moment) will have on a particular response variable at a node or element. For example, you are modelling a doubler
plate, where minimising the centre deflection is of importance. You would assign a vertical displacement response
variable to the centre node and run the Load Influence solver. The results will allow you to determine the loading
location that generates the largest centre deflection.
There are a number of response variables that can be assigned to the different element
types in Strand7. For nodes you can specify displacement or reaction, in a UCS or the
global Cartesian system. For beams you can specify axial and shear force, bending
moments and torque. For plates you can specify forces and moments, and for bricks
you can specify stresses. Any number of response variables can be solved with each run
of the solver – effectively each response variable generates a pseudo load case for the
solver.
Once the required response variables are assigned you can run the Load Influence solver.
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In the example on the right we
have a simply supported beam with
a vertical support near the right
hand end. A bending moment
response variable is assigned as
indicated. The results show that a
vertical unit force applied near the
point of interest will give a bending
moment of –117.551 Nmm at the
location of the response variable.
Alternatively a unit force applied
near the right hand end will give a
bending moment of 9.524 Nmm at
the response variable location.
•
Load Paths
The Load Influence solver can be used independently or in conjunction with the load path options. The Strand7
Moving Load module, including the load path template has been designed to fully support a number of different
moving load codes including AS5100, BS5400, EN 1991-2:2003 and AASHTO LRFD Bridge Design
Specifications.
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What’s New in Strand7 Release 2.4
Vehicles in the load path template can be defined as point loads or distributed loads. While point loads can be
grouped or floating, distributed loads can be leading, trailing, floating or grouped as per the different moving load
codes. Coupled with this there can be leading and trailing load voids.
The different loads can be assigned to define all vehicle templates specified by the codes; this includes HA and HB
vehicular loads and railway loads as used in BS5400. The loads can be user defined, or imported from a standard
load path template. A number of templates are shipped with Strand7 R2.4; these define the different vehicle
configurations specified in the national codes.
Loads can be defined in any direction in either the local or global coordinate systems, making it easy to define
braking or centrifugal loads where required.
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What’s New in Strand7 Release 2.4
Up to 16 lanes can be modeled in Strand7 and different factors can be
applied to each lane if required.
Lane factors may be applied to comply with various codes, e.g. AASHTO or
AS 5100.
These factors are considered if Adjacency is set in the load definitions.
Centrifugal loads can be applied to the load path automatically by entering
an equation. This means that if the radius is changed, the loads don’t have to
be manually changed but instead will automatically update.
Centrifugal loads are considered if Centrifugal is set in the load definitions.
Vehicles can also be single or multiple instance and may also straddle
adjacent lanes.
Both concentrated and distributed loads may act simultaneously on any lane.
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Sets can be specified to ensure that vehicles are restricted in number if
required. This is particularly useful if you are working with the British code.
Load paths can be created over any element type in
Strand7. They can be straight or curved and are
independent of the mesh density of the underlying
elements. This means that if the load path only partially
lies on one element then load will only be placed on
part of the element. It also means that if the underlying
mesh is changed, e.g. refined, then no additional work is
required to define the load path.
If, at a later stage, changes need to be made to the load
path then individual attributes such as Load Path
Template Type, group, loaded elements and divisions
can be easily changed.
Load paths can also be copied, moved, scaled, etc,
similarly to elements in Strand7.
•
Convert Load Paths to Load Cases
Load Paths can be converted into Load Cases via Tools/Convert/Load Paths to Load Cases. The Load Cases will
consist of vehicles at consecutive positions on each lane. This tool offers an alternative to the Load Influence
approach to finding maximum results responses.
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What’s New in Strand7 Release 2.4
•
Load Influence Combinations
Load Paths can be
combined with response
variables to generate Load
Influence Combinations.
With this Strand7 will
automatically determine
critical load combinations
based on the included
variables and whether the
maximum or minimum
response is required.
Load Influence Combinations can be either Single Variables or Multi Variables, depending on whether you require
the Max and Min response of individual response variables, or combinations of them. For example, you can find the
load combination to generate the maximum reaction at a single node, or the load combination to generate the
maximum reaction sum at multiple nodes. Once generated, new load cases will be created in the model that
corresponds to the load influence combinations that apply the critical load to the model. These additional load cases
are treated as regular load cases and therefore may be combined with other loads.
•
Dynamically Moving Load
A dynamic moving load can also be modelled using this option, generating time dependent loads for the dynamic
solvers. The load (vehicle) velocity and start time are assigned to a specific vehicle in a load path template and then
when either the Quasi Static or a Transient Dynamic solver is used the load will travel along the load path across the
elements. This is a true moving load, and results such as displacement or stress can be extracted for part of, or the
entire, solution time.
Click
Clickto
to Animate
Animate
As well as moving point and distributed loads, a moving heat source can also be modelled. This is for use only with
the Transient Heat solver and allows for easier modelling of situations where the change in heat across a surface is
important in the process, e.g. moving heat flux during a welding operation.
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New Element Attributes
ID Attribute
Nodes and entities (including geometry) in Strand7 can now be assigned an ID, which can be any whole number.
This ID can be assigned on an individual level or to a group of entities. It is separate from node or element
numbering and will not change when the mesh is reordered or entities are added or deleted from the model.
Offset Non-Structural Mass
Non-structural masses can be offset in any direction in either the global or user defined
coordinate system.
Node Heat Source
A heat source can now be assigned at the node level. A Factor vs Time or Factor vs Temperature table can be
associated with this.
Node Velocity
A nodal velocity can be assigned in the global coordinate system or a UCS. This is used in the transient dynamic
solvers as initial velocity and is particularly useful for modelling impact situations where one part of the structure is
moving relative to another.
Node Acceleration
A nodal acceleration can also be assigned in the global coordinate system or a UCS. This allows you to accelerate
only specific components of a model, which is not possible using global accelerations which act on the whole model.
External Pipe Temperature
The external (or outer) pipe temperature can be assigned a specific value or alternatively simply set to the nodal
temperatures of the element.
Pipe Axial Force
When a pressure is assigned to a pipe element, the option can be set to Include Axial Force. This accounts for the
axial force generated by pressure acting on a closed ended pipe.
Connection UCS
A UCS can be assigned to either or both ends of a connection beam to define the
stiffness axis system to be other than the Global one.
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What’s New in Strand7 Release 2.4
Tapered Beam
Previously in Strand7 a tapered
beam was created by using the
Interpolate Beam Sections tool.
There is now a purpose built
tapered beam element. The
tapered beam attribute allows a
beam to be tapered by any amount
from one end to the other and be
symmetric or skewed to the top or
bottom.
This is applicable for any standard
beam cross section, including BXS
sections.
If a tapered beam is subdivided the
attribute for each new beam is
automatically applied such that the
original taper is maintained.
Subdivided beam
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Beam Stiffness/Mass Factor
Beam stiffness or mass values can be scaled outside the beam property dialog.
Individual beams can have factored bending stiffness, axial stiffness, etc. This is similar
to the ability to have a plate thickness for an individual plate element separate to the
thickness defined in its property type.
If a scaling factor is used, this can be contoured on the beam using Entity Display
Contours, e.g. Scaled EA, etc.
If a Mass scaling factor is used this will be reflected in Summary/Model.
Plate Point Force
A point force can be applied to a plate anywhere on its surface. The location for the
point force can be defined by using either global or UCS coordinates or the local u, v
coordinates of the plate.
Plate Point Moment
Similar to the Plate Point Force, a point moment can be applied anywhere on the surface of a plate.
Plate Surface Convection
Previously, in order to model convection normal to a surface a brick mesh was
required. In R2.4 we have introduced the ability to assign convection, both
coefficients and ambient temperature, normal to the surface of a plate. Similar to plate
edge heat transfer it can also be linked to a Factor vs Time or Factor vs Temperature
table. Additionally you can choose for the convection to be on either the +z or –z
surface of the plate or both surfaces.
Plate Surface Radiation
Similarly to plate surface convection, radiation coefficients and ambient temperature can be assigned normal to the
surface of a plate.
Brick Point Force
A point force can be applied to any location on any face of a brick similarly to the plate point force.
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Beam/Plate/Brick Preload
The preload on a beam element can be assigned as either a pre-tension or a pre-strain.
Similarly plate and brick elements can be assigned a pre-stress or a pre-strain.
Attachment Attribute
The attachment attribute can be applied to beams, plates, bricks and faces. This attribute is used in conjunction
with the attachment link when connecting incompatible meshes. The attribute is designed to define the regions of
the mesh which are to be attached to other parts of the mesh via the automatic attachment tool. Using this
attribute means that if the mesh is refined, it is very easy to re-establish the connections between dissimilar meshes.
Contact Pre Strain
A pre strain can be assigned to point contact elements. This provides the ability to change the location of contact.
Groups Attribute
Elements can now be assigned to groups via the attributes menu, Attributes/Beam/Group.
Link Type
Link types and attributes are now edited via the attribute menu under Attributes/Link/Type. Links can also be
assigned to specific groups via the attributes menu as per the element methodology.
Age at First Loading
The age when an element is first loaded can be applied at the attribute level. This attribute is used in a concrete
creep analysis. By default the age at first loading is set at the property level, however like plate thickness, it can be
set on an element level as an attribute, overriding the property setting.
Steady State Temperature Import
When importing temperatures from a previously run heat analysis, temperatures can be selected from a specific result
case of a steady state heat solution.
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What’s New in Strand7 Release 2.4
Attribute Summary
A summary of all node
and element attributes
existing in a model is
given in the
Summary/Attributes
spreadsheet. An
important feature of this
summary is that it also
sums the applied loads for
each attribute type,
allowing you to determine
the total applied loads
before solving the model.
Online Editor
Where an attribute, e.g. Face Convection Coefficient, has a table assigned to it, the table name is now included in
the online editor. It is also possible to change the assigned table in the online editor.
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New Material Types
Creep
Creep behaviour can now be modelled in Strand7 for beam, plate and brick elements. Two different types of creep
analyses are available: concrete creep and shrinkage and creep following the von Mises stress criteria.
•
Concrete Creep and Shrinkage
Under the Property menu Creep is
selected for defining specific creep data
for your model. Various creep laws are
available with the first three dedicated
to concrete creep and shrinkage.
The Hyperbolic Law is commonly
used by concrete design codes CEBFIP1990 (European) and ACI209
(American). The coefficients in
Strand7 can be directly matched to the
coefficients in these design codes.
Other codes or experimental data can be accommodated via the User Defined creep law. Using this law you may
enter a number of Strain vs Time tables that can be referenced during the solution. Concrete design codes such as
AS3600 (Australian) and BS8110 (British) can be addressed via this law.
The third concrete creep and shrinkage law available is Viscoelastic Chain. This allows you to directly specify
Kelvin or Maxwell chains to model creep behaviour.
Each of these three laws allows for shrinkage to be modelled as well as creep. The data can be entered as a strain vs
time table or via a shrinkage formula based on specific code requirements.
Finally temperature effects can be included for both the creep and shrinkage of the concrete.
For concrete creep the age at first loading is an important consideration and as such can be included at either the
creep property level or as an element attribute.
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What’s New in Strand7 Release 2.4
Creep data is assigned to individual properties
via the Nonlinear tab of the property dialog.
Once the creep data has been assigned and loads and/or temperatures have been included the model can be solved
using the Quasi Static or the Nonlinear Transient Dynamic solvers.
Displacements, stresses, strains, etc, can
be extracted from the model as per a
normal time dependent analysis. In
addition to this it is also possible to
extract, creep and shrinkage strains for
the concrete creep material.
•
von Mises Creep
The second creep analysis that can be conducted is creep using the von Mises stress criterion. This method is
commonly used for the creep of metals but is not restricted to just these materials. Like concrete creep, the relevant
law is defined via the Property/Creep dialog.
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There are various creep laws
that can be used for von
Mises creep. The most
common of these are the
three Power Laws. For most
of these laws the relevant
coefficients need to be
entered to define the
material model.
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The von Mises creep option may also
be used with a User Defined Creep
law. This allows you to enter a range
of Strain vs Time tables that
correspond to different stress and/or
concrete age at first loading.
For a number of the creep laws, the creep rate can be based on Time or Strain Hardening. Within Strand7, the
hardening method is selected in the creep property dialog. If strain hardening is selected then an additional ‘Cyclic’
option is available to properly account for cyclic loading.
Once the creep properties are defined they are assigned to the appropriate properties in the model via the nonlinear
tab in the same way as the concrete creep was assigned.
The Quasi Static and Nonlinear Transient Dynamic solvers can then be used. Data for von Mises creep can be used
in conjunction with a von Mises Nonlinear Elastic or Elastic-Plastic material model.
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What’s New in Strand7 Release 2.4
Similarly to concrete creep it is possible
to extract displacements, stresses,
strains, etc, from the model. As well as
this you can post process the creep
strain and the effective creep rate for
the model.
Brick Soil Model
Soil is now available as a material type for brick elements. This allows you to assign either the Duncan-Chang soil
model or any of the new soil models below (e.g. Modified Cam-Clay soil model).
Modified Cam-Clay Soil
A new soil material model has been developed that is based on critical state mechanics. The Cam-Clay model is a
widely used plasticity model for soil. Features of this soil model include being able to consider the sensitivity to
pressure, dilatancy of the soil, hardening and softening and fluid/pore pressure, depending on whether the soil is
drained or undrained. This material model is available for plane strain, axisymmetric and 3D brick elements.
Modified Cam-Clay is assigned at the property
level under Material. Here you enter the various
required properties including Critical state line
slope, Soil mass density and Swelling Line
Slope.
These values are often taken from published
data.
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Under the In-situ tab you can enter data relating the stresses in
the model, e.g. Horizontal Stress Ratio, Void Ratio, etc.
This in-situ data can also be controlled at the attribute level for
both plates and bricks, e.g. Attributes/Plate/Soil/In-situ Stress.
The Fluid tab is used to specify whether the soil is Drained or
Undrained.
You can also specify whether the Fluid Level in the soil is the
Default Level, as set in the solver dialog, or a Set Level. This
allows different fluid levels to be set throughout the model.
Modified Cam-Clay is a nonlinear material model and as such needs to be run using one of the Nonlinear solvers,
i.e. Nonlinear Static, Quasi Static or Nonlinear Transient Dynamic.
It is important to specify in the solver dialog the load case
that defines the direction of gravity. Here you also specify
the Level and density of the fluid (usually water).
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What’s New in Strand7 Release 2.4
A result Quantity option exists for post
processing of soil models. This allows you to
view quantities such as Total Pore Pressure,
OCR (over consolidation ratio) and the Failure
Index for the soil. It is also possible to look at
displacements, stresses, forces, etc., for the soil
structure.
Mohr-Coulomb Soil
The Mohr-Coulomb Soil model is a generalised form of the Coulomb friction failure law which considers additional
effects from the water content, void ratio, and in-situ stresses. This soil material model is usually easier to define
because of a higher availability of its parameters.
Drucker-Prager Soil
The Drucker-Prager Soil model is an approximation to the Mohr-Coulomb Soil model which also considers
additional effects from the water content, void ratio, and in-situ stresses. This soil material model is usually easier to
define because of a higher availability of its parameters.
Linear Elastic Soil
The new Linear Elastic Soil model is an isotropic soil material that never yields. It considers the effects from water
content, void ratio, and in-situ stresses. This model requires the least number of material parameters to work and is
particularly useful in conjunction with the other soil models available.
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What’s New in Strand7 Release 2.4
Fluid Material
Strand7 R2.4 includes a new fluid material model for
2D plane strain, axisymmetric and 3D brick analysis.
The fluid material model is used to model fluidstructure interaction such as fluid filled tanks.
Click
Click to
to Animate
Animate
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New Material Options
Nonlinear Beam
Beam elements can now be assigned a stress vs
strain curve for material nonlinear analysis
without the need to define nonlinear momentcurvature tables. The main advantage of the
new functionality is that the nonlinear
behaviour (axial, bending and coupled axialbending) can now be defined automatically
once the section shape and the material curve
are defined. Uncoupled axial stress vs strain
and moment vs curvature tables can still be
assigned as an option.
The yield stress used by the beam is the fibre
stress, which can be positive or negative. As
such the stress vs strain table can have different
tension and compression parts to the curve. If
the curve is only defined in the positive
quadrant, the solver will assume the table is
symmetric whenever the fibre stress is found to
be negative.
Brick Bubble Function
In previous releases of Strand7, the bubble function for Hex8 elements was automatically included. In R2.4 there is
the option to not include the bubble function. This can be set via the Elements tab in the Brick Property dialog.
Load Patch Tolerance
A tolerance exists to determine whether a beam lies on a load patch plate. This is set in the property dialog for the
load patch. A beam is deemed to lie on a patch plate if the distance is within Tolerance × Average plate edge length.
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Point Contact Friction Model
A new contact friction model has been
developed for R2.4.
The yield surface, the boundary between stick
and slide, can be set as either Rectangular or
Elliptical.
For the Rectangular yield surface, the stick or
slide in the 1 direction is independent of the
stick or slide state in the 2 direction.
For the Elliptical yield surface, the stick or slide
state is coupled in the 1 and 2 directions.
There is also the option of for the friction
model to be Elastic or Plastic, which defines
the behaviour of the point contact once the
shear force exceeds the yield surface.
Elastic causes the stiffness to be set such that
the shear force does not exceed yield. The
centre of the yield surface is not updated.
Plastic causes the shear deformation of the
contact to be non-recoverable and the centre of
the yield surface is updated.
In addition the Sliding Friction Factor can be set in the solver Defaults under Elements. This gives a tangent
stiffness when the contact is considered to be sliding.
Elastic or Plastic Temperature and Time Tables
In the Elastic option, the Factor vs Time/Temperature table
associated with the property establishes the state of equilibrium at
a particular instant, and this equilibrium is not affected by the
history of the table prior to this instant. So in the case of a
constant loading situation, the displacement in the mesh will be
directly related to the table values.
In the Plastic option, the Factor vs Time/Temperature table
associated with a property establishes the increment in
displacement for an increment in load, i.e. if the loading does not
change, then displacement remains constant irrespective of values
in the table.
This option is available for beams, plates and bricks.
Export BXS
Within the beam property dialog there is the option to Export BXS to File
. With this feature you can export
the section data for a BXS beam to create a new BXS file. This is an advantage if the original Strand7 file used to
make the BXS or the original BXS file are no longer available.
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Automatic Rubber Constants
The constants required for the Neo-Hookean, Mooney-Rivlin and
Ogden rubber models can be automatically calculated by Strand7 R2.4.
Test data for a given rubber specimen can be included by way of a
Force vs Displacement or Stress vs Strain table and Strand7 will
convert this to a Stress vs Stretch table and determine the appropriate
constants. The Poisson's ratio is used to calculate the rubber bulk
modulus. A warning is issued when the interpolation produces curves
with negative gradients.
3D Membrane Laminates
3D Membrane plate elements can make use of the laminate material type, where only the laminate membrane
stiffness is considered.
Ply Shear Modulus G13 and G23
Shear moduli in the 13 and 23 directions can be entered as part of the ply properties.
Orthotropic Plate Shear Modulus G13 and G23
Shear moduli in the 13 and 23 directions can be entered as part of the orthotropic plate properties.
Invert Plies
A symmetric laminate can be easily created using Invert Plies
in the
laminate property dialog. This tool allows you to set the first and last rows to be
inverted. Using this method all columns associated with the row are inverted. If
only specified columns or values are to be inverted, right click and select Invert
Selected from the menu.
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Laminate Matrices
The stiffness matrix for a laminate stack can be viewed by clicking View Matrices in the plate property dialog as well
as the laminate layup dialog.
Ply Thickness
Ply thickness can now be assigned at the laminate stack definition stage, in addition to the assignment at the ply
property level. If assigned at the stack definition stage, these values override the values in the ply property
definition.
Truss Torsion Constant
As well as the area, a truss element can include the torsional stiffness.
Truss Poisson’s Ratio/Shear Modulus
The truss element now supports the input of a Poisson’s ratio or shear modulus.
Automatic Laminate
Transverse Shear
The transverse shear stiffness for a
laminate becomes more and more
important as a laminate gets thicker.
Previously these values could be
manually entered, however in R2.4
these values can be automatically
calculated by Strand7, saving time on
complex hand calculations.
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Mirrored Beam Torsion Constant
Compatible twist controls how the torsional constant, J, for a mirrored
section is calculated. If set, it is assumed the mirrored sections are “glued”
together in twist. If not set it is assumed that the torsional stiffness is the
sum of the individual parts.
Shear Centre
When defining beam cross section
geometry, if Exact J and SA is
set, the exact value of shear centre
is calculated for that section, in
addition to the previously
available torsion constant. The
algorithm used for this operation
is the same as that used by the
BXS generator.
Reorder Property Sets
Property names in the property dialog can be reordered to a user defined order, automatically updating all the
elements that use those properties.
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Beam/Truss Integration Points
Integration Points is available for beam and truss elements. This
controls two aspects of the beam. The first is the number of sections
the tapered beam is sliced into for internal calculations. The second is
how many sections the beam is sliced into for material nonlinear
analysis.
Beam Cross Section Discretisation
The user can control how the beam cross section is discretised for
material and/or creep analysis. The specific controls will change
depending on the type of cross section, i.e. circular, BXS, etc.
Yield vs Temperature
For all beam, plate and brick properties that allow tables vs temperature assigned there is the option to assign a Yield
vs Temperature table. Applying this table to a property accommodates when the yield varies according to the
temperature.
Auto-Assign Soil In-situ Stress
The Auto Assign Soil In-situ Stress tool is used to automatically assign the In-situ Stress attributes to soil elements.
The initial vertical stress distribution is determined based on the elevation of the element with respect to the fluid
level and the, unit weight and other material parameters. The horizontal stresses are set as the product of the
vertical stress and the Default Horizontal Stress Ratio (K0). Soil In-situ Stress is an Effective Stress, not the Total
Stress, i.e. the Pore Pressure is not included in the In-situ Stress.
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New Table Options
Elastic Modulus for Tables
The elastic modulus, Eo, for any stress vs strain table will be given in the status bar.
Factor vs Frequency Table
Units
Factor vs Frequency/Period tables can
have the units for the factor specified.
These units can be for displacement,
velocity or acceleration response or
PSD. If a particular unit is specified
then this table can only be used for the
corresponding loading in the solver.
For example if a Velocity Response
table is created, the table will only be
available to be assigned to a Base
Velocity Response loading situation in
the solver dialog. The availability of
units on the tables also means that if the
model units are changed, the table is
still consistent with the model.
Summary Table
Summary/Table
provides a count of
all the tables
existing in a model
as well as a list of
the names for each
table type.
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Factor vs Position Table
Loads on an element can be factored based
on their position in any one axis by assigning
a Factor vs Position table. This table can be
used in a Nonlinear Transient Dynamic
analysis and is particularly useful for marine
craft. For example, when a boat moves up
out of the water the pressures on the sections
above the water are now zero while those
below remain loaded. Assigning a Factor vs
Position table to the water pressure load case
allows you to simulate this situation and
effectively perform buoyancy analysis.
Click
Click to
to Animate
Animate
Strain vs Time Tables
Strain vs Time tables can be created to be used in conjunction with user defined concrete and von Mises creep
analyses.
Symmetric Stress vs Strain Tables
When a Ramberg-Osgood or Elasto-Plastic stress vs strain table is generated, the Symmetric option can be set. This
will generate the same curve but in the opposite quadrant, e.g. the positive stress, positive strain curve will be
mirrored in the negative stress, negative strain quadrant. This is useful for nonlinear elastic analysis where the
tension and compression characteristics are important.
Spreadsheet Right-Click Options
New quick select and edit options are available in the spreadsheets such as Online Editor and Tables:
•
Select/Unselect Highlighted – Selects/Unselects those elements in the model belonging to the highlighted
cells in the spreadsheet.
•
Select Row/Column – Selects a row or column of data.
•
Replace/Scale/Add To Selected Cells – Replaces, scales, or add a constant to the value of selected cells in
the spreadsheet.
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New Solver Options
3GB RAM
The Strand7 solver can now use a total of 3GB of RAM. Some changes to WinXP settings are required but these
changes will not affect the performance of your system. Information on the changes required can be found in the
Strand7 Online Help.
Quasi Static Solver
The Quasi Static solver allows for the
calculation of the time dependent
response of a structure subject to
arbitrary loadings and/or initial
conditions, but ignores any dynamic
(inertia) effects.
Load Influence Solver
The Load Influence solver is now available in Strand7. It generates influence lines and influence surfaces for any
desired response variable. The Load Influence solver can be used to determine the effect that a unit load will have
on a particular response at an element or node. For example, if you are interested in vertical displacement at a node,
the Load Influence solver can be used to find what effect a unit load at each location on the mesh will have on the
vertical displacement at that node. In this way you can determine worst case loading scenarios. This solver can be
used independently or in conjunction with the moving load options.
Iterative (PCG) Solver
A new iterative solver based on the preconditioned conjugate gradient method, is available for each of the solvers in
Strand7. This is not a direct solver but instead iterates towards a converged solution. This solving scheme performs
best when solving large brick models, particularly automeshed Tet10 models. It will also be beneficial for models
that have a stiffness matrix above the supported limit for the direct sparse solver.
The PCG solver is available for the Linear Static, Nonlinear Static, Load Influence, Quasi-Static and Steady State
Heat solvers.
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Initial PCG
When the Linear Static solver is run, there is
the option to select a previous solution file as
the initial estimate for the PCG solution.
This is beneficial in models with multiple load
cases, only some of which have changed. The
solution will be faster as unchanged load cases
will converge immediately.
Add Nonlinear Iterations
When set, Allow Solver to Add Iterations
(Defaults/Iteration) will add extra iterations
above the specified limit rather than sub-step. This
will however only occur if it is detected that the
force norm is reducing.
Nonlinear Solver Defaults – Sub-steps
Sub incrementing in Strand7 R2.4 has
a variety of user controlled options.
None
No sub-stepping is used.
Load Scaling
This is the same as the subincrementation used in previous
releases of Strand7. The load is halved
when required. This is good for
softening type structures.
Displacement Scaling
The new load used for the sub-step is
calculated as the load required to give
only half the change in displacement
for that step. This is good for stress
stiffening type structures.
Displacement Control (Arc Length)
This uses the arc length method to
subincrement. This is useful for snap
through and snap back problems e.g
tracking buckling of structures.
If the quasistatic or nonlinear transient solvers are used, the Sub-steps dialog changes to reflect the time stepping
solver. In this case the Sub-step options are None or Time Step Reduction.
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Nonlinear Solver Defaults – Nonlinear
In the Nonlinear section of the
defaults tab you can now have some
control over the modulus that is
used to form the stiffness matrix in a
nonlinear beam or 2D or 3D
nonlinear elastic analysis.
Stable principally uses the E0 for
nonlinear beams and the secant
modulus for 2D and 3D nonlinear
elasticity. This method is slow but
very stable.
Fast principally uses the tangent
modulus. This method is fast but
can be unstable.
The slider can be moved to adjust
which modulus is principally used.
For a properly converged solution
there should be little difference
between the results for the different
methods.
When KG is included, the matrix is formed based on the current stress state. There are two further options:
Autoscaling adjusts KG at each iteration.
Ignore Beams in Compression will consider KG only for beams that are not in compression, providing more
stability for the solution if only some of the model is in compression.
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GNL Beam Length
In the Solver dialog, under Defaults/Nonlinear, you
can set whether Strand7 considers the original length
or the updated length when calculating moments. This
is particularly of interest in large axial strain problems,
e.g. thermal strain on a beam to simulate a telescopic
arm.
2000mm
1000mm
In the example on the right the beam is extended by
1000mm using a thermal strain. A 50N load is applied
to the end of the beam.
If the Initial length of the beam is considered the
moment at the fixed end would be
50 × 1000 = 50000Nmm. However if Update is
selected the new length is considered giving a moment
of 50 × 2000 = 100000Nmm.
Include Rotational Mass
The rotational mass of a structure can be excluded from an analysis if required. This is useful if theoretical results are
to be matched. The setting for this is in the Defaults tab of the solver dialog under Elements.
32 Gigabyte Limit
The size limits for the global stiffness matrix has been increased from 16GB to 32GB.
Multiple Load/Freedom Cases in Linear Static and Heat Transfer Analysis
The Linear Static and Steady State Heat solvers can now be used to solve for multiple load/freedom cases in one
batch run. For Linear Static analysis, each individual freedom case can be solved in conjunction with selected load
cases and all the combinations of freedom case/load case are then stored in the one result file, greatly simplifying the
combinations of result cases across different freedom cases. When analysing the results the result case dropdown will
list each load and freedom case combination in the solution file.
Multiple Transient Heat Load Cases
Multiple load cases can be solved for in a transient heat analysis. Note that only one nodal temperature case can be
solved for in a single solve as this is similar to a restraint case.
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Load Case Selection
There is a new method for selecting load and freedom
cases to solve for in the Linear Static solver. This has
been developed to make multiple freedom case solves
easier.
A solve will be completed for each load case per
freedom case that is selected. This allows you to
include only those load and freedom case combinations
that are required.
This also applies to the Load Influence solver.
Automatic Submodel Load and Freedom Cases
If a submodel is created from a model with multiple primary and secondary load cases, the correct load and
submodel freedom cases will be paired in the linear static load case dialog.
Rotational Mass Participation
In addition to the previously available
translational mass participation, the
rotational mass participation about a
specified axis can now be calculated in
the Natural Frequency solver.
Modal Stiffness
When mode participation is calculated for a natural frequency solution, the log file will report the modal stiffness in
addition to the modal mass and participation.
Terminating Batch Solves
When running a batch or multiple freedom case solution terminating the solution will present the option of
terminating only the current run or all subsequent runs.
Stop After This Iteration
The stop after this iteration button
has been enabled for a variety of solvers in Strand7. The different
messages, indicating the different outcomes for each solver, are presented below.
•
•
•
Linear Buckling, Natural Frequency and Steady State Heat
- terminate the solution after this iteration and accept the current results.
Nonlinear Static
- accept the results for the current increment and proceed to the next increment.
Nonlinear Transient Dynamic, Quasi Static and Transient Heat
- accept the results for the current time step and proceed to the next time step.
Nonlinear Convergence Plotting
The convergence or a Nonlinear Static, Nonlinear Transient Dynamic, Quasistatic and Nonlinear Steady State Heat
analysis can be graphed in Strand7 Release 2.4. This allows you to easily see whether a solution is converging
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quickly, slowly or diverging for a particular load increment or timestep. Click
Current step or a specified Single step.
to show a graph for All steps, the
Solve-Batch-Cancel
The Solve, Batch and Cancel buttons are now visible independent of the tab in the solver dialog that is selected.
Close Graphics on Solve is also permanently visible.
Frequency File Selection
When a frequency file is selected for use in
spectral response, harmonic response or linear
transient analysis, whether the frequency is
converged is also indicated. This allows you to
avoid including unconverged modes in further
analyses.
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Autoinsert Harmonic Frequency Steps
The harmonic solver now has an option to calculate results for exactly the number of Steps
requested or to Autoinsert Steps for the natural frequencies and half power points.
Auto Shift for Rigid Body Motion
When a possible rigid body mode is detected in the natural
frequency solver, the option can be set to automatically apply
a shift to allow the solution to proceed. This option is located
in solver Defaults/Eigenvalue.
Calculate Results for Specific
Properties or Groups
In addition to the ability to calculate
specific quantities like node reaction
and plate strain, you can now choose
to calculate results for specific
elements. In the solver dialog,
groups or property types for each
element can be selected so that
results are saved for only these
elements. For example, in this
model we are only interested in the
stresses in the metal strip as the
cylinder is used as formwork. Thus
we have only saved the stresses for
the Metal Strip group.
You can also enter plate and/or
brick stress limits that ensure that
only results for elements with stresses
above these limits are saved.
The final file size saving feature of this dialog, Beam Fibre Stress (MNL) relates to nonlinear static, nonlinear
transient dynamic and quasi-static solutions. If set then the nonlinear beam fibre stresses are saved. If not set, any
beam elements that have yielded will be shown in wireframe when fibre stress is contoured.
For large models this will mean not only a saving in solution time but also make it easier to process results as the
results files will be much smaller.
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Rayleigh Curve
The Rayleigh Damping curve
can be drawn to show the
effective damping coefficient for
a given frequency range using
the equation ζ = 1  α + βω  .
2ω

This allows you to see the actual
amount of damping being
applied to your structure over
different frequency ranges.
Automatically Create Load Increments
Nonlinear load increments can be created automatically
in Strand7 R2.4
. This feature allows for the
Start and End factors and Increments to be entered.
This tool is also available when a construction sequence
is being run and stages have been included.
Reset Increment Totals
Within the nonlinear load increment table, the number of load increments can be reset in one step via Reset
Increment Totals
. This avoids the need for multiple Delete or Add operations.
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Soil/Fluid Solver Options
The Soil/Fluid Options dialog within the solver allows for
a number of options to be specified.
The main one of these is the definition of the load case
that specifies the gravity direction for both the soil and
fluid elements.
The Default Level specifies the level of the fluid in the
soil.
The water button
allows for the automatic
assignment of values for the Mass Density and Bulk
Modulus of water.
This is available in all solvers except harmonic response,
spectral response and the heat solvers.
Elastic/Plastic Tri3
The Tri3 element can now be used for both elastic and elastic/plastic analysis.
Coupled Tri3
The membrane and bending is coupled for a Tri3 element when nonlinear elastic or elastic/plastic analysis is being
performed.
Add Time Steps
Within the linear and nonlinear transient and quasistatic solver load tables dialogs the option to Add
Time Steps has been included. When set, if a Time
Table is also present, extra time steps will be added
corresponding to each point on the Factor vs Time
table. This is in addition to the specified Time Steps
and will ensure that nothing in the time table is
missed.
Compression Only Support Stiffness Scaling
An option to scale the compression only support stiffness during nonlinear solver iterations is available in the Solver
Defaults/Nonlinear section. This option can improve convergence in some situations.
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New Results Options
Element Node Reaction Forces (Free Body Diagrams)
Previously nodal forces were only available at restrained nodes (node reactions). Forces can now be extracted from a
model from any node, whether restrained or internal to the model. These are the element forces generated by the
element deformation; at any node they sum to zero whenever all the elements connected to that node, plus any
loading at the node, are considered.
If only parts of a mesh are displayed a free body diagram for only those sections displayed will be shown.
In previous releases of Strand7 a submodel was required to find the internal node reactions.
Reactions at Nodes
Results Settings allows you to specify which nodes are to have their reactions contoured.
You can choose to show the reactions of all nodes, only the fixed nodes or only the free
nodes. This can be useful when trying to determine areas of non-convergence in a
nonlinear static analysis. Here you would look at the reaction forces of the free nodes
only to find areas of the model that require modification.
Beam Axial and Bending Stress in Results Listings
Minimum and maximum axial and bending stresses can be extracted from the results listings for beam elements.
Plane Strain local zz
The local zz stress can be extracted from a plane strain model.
Beam End Viewing
In addition to the previously available View: Beam Ends in Results Listings there is now also View: Beam end 1
and View: Beam end 2.
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Elastic Support Stress Results (Bearing
Pressure)
Elastic Support stresses can be extracted from Strand7
results at the nodes for both edge and face supports.
These can be contoured, peeked, graphed or viewed in
results listings.
Combine Results
Files
Up to 32 individual result
files can be included at
once within Combine
Results Files. In
addition, combination
factors for the new result
file can be retrieved by
reopening a previously
combined file as the
Target file.
Linear Load Case Combinations of Combined Results Files
Linear Load Case Combinations can be created based on Combined Results files generated by the user.
Re-generate Linear Load Case Combinations
If changes are made to the linear load case combinations when results are open they can be re-generated without
closing the results.
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Element Result Range
A contour averaging option is available that
displays the maximum nodal range for the
displayed result. Similar to jumps this contour is
useful for mesh verification purposes.
User Defined Min/Max Settings
The user defined range for results settings can be defined by either a maximum, a minimum, or both. The limits are
now also stored separately for each result type, e.g. displacement, stress, etc.
Surface and Midplane Ply Stresses in Laminates
Ply stresses can be extracted for the midplane, +z and –z surfaces in the same way plate stresses can.
Animation AVI
Strand7 animations can now be saved as AVI files as well as the previously available executables and saf files.
Beam Displacement in
Peek/Listings
Displacements at points along the
length of the beam can be extracted
from the peek tool and results listings.
The number of positions given is
dependent on the number of slices set
in the beam Results Settings.
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Beam Results in the Local System
As well as the previously available principal axis beam results, quantities such as shear force and bending moment can
now be given in the beam local axis system. This makes it easier to perform design code checks for beam cross
sections such as angled section where the moment aligned with the section is required. These results are also
available in the results listings, graph and peek tool.
Principal beam bending moment
Local beam bending moment
Beam Yield Ratio
A new stress option, Yield Ratio, has been introduced for
nonlinear material analyses. When an elastic-plastic analysis is
conducted the Yield Ratio will display the percentage of cross
section that has yielded, e.g. 0.75 means 75% of the cross section
of the beam has yielded. The Yield Ratio can vary along the length
as one end of a beam (or plate or brick Gauss point) can be yielded
while the other hasn’t. The yield ratio is also available in the peek
tool.
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Node Averaging
Node averaging options similar to that previously only available
for results contours is available in the peek tool. The nodal
values shown for a particular plate or brick can be never averaged
(as was previously given in the peek tool), always averaged, or
averaged across the same property.
This is also available in the Results Listings.
User Defined Results in Plates/Bricks
Results Settings and the Peek tool allow the creation of userdefined results quantities. An equation that utilises any
component of stress, strain, force, moment or curvature value
can be defined. Strand7 evaluates this at each Gauss point or
node as required.
This result can be given a unique name and contoured, peeked,
graphed and viewed in the results listings.
The user defined result definition can be generated or edited in
the results settings and peek tool.
Equations can be defined using the dialog box shown or may
be copied from a text file, e.g. Notepad, and pasted into the
equation window.
Deviatoric and Mean Stresses
Mean and deviatoric local and combined stresses are available.
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SRSS and CQC Combined Results
When modal results are saved, combined results
are available for SRSS and CQC solutions in the
Spectral Response Solver. This includes
quantities such as principal stress, stresses in a
UCS, etc., and is supported by all the element
types.
View Load Factors
Choose Results/View/Load Factors when the results are open to view the
load factors used for the current linear load case combination. The factors
used for a particular increment or time step in nonlinear static, linear and
nonlinear transient dynamic analyses as well as the factors in combine results
files are also available via this dialog.
Entity Inspector Attributes
With the results open it is now possible to use the Entity Inspector (hold Shift
down while hovering over an entity) to display the attributes assigned to a
given element for each result case. For linear load case combinations,
nonlinear static increments and transient dynamic time steps the attributes
shown will consider any factors applied and the values given will be scaled
accordingly.
Attribute Display in Results
With the results open, attributes will be displayed on the elements according to the active result case. This includes
linear load case combinations, nonlinear static results and transient dynamic time steps where the attributes shown
will consider any factors applied.
Reactions Listings
In the Results Listing you can choose to show reactions for all nodes or restrained nodes only.
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Gauss Point
Location
When using the
Peek tool the
location of the
Gauss points for
plate and brick
elements will be
displayed. This will
allow comparisons
to be made
between specific
Gauss points and
the nodal values
extrapolated from
them, further
aiding verification
of models.
Results Listing Value Coordinates
XYZ coordinates for the nodes, centroid and gauss point results can be shown in the results listings alongside the
result value. These three columns, Y, Y and Z, can be turned on and off as required.
Results Listing Summary
When viewing the node value summary or gauss point value summary for element results in results listing the
node or gauss point number, shown in brackets, can be turned on or off. Right click the screen and select Show
Summary Locations.
Animation Selection
When only selected result cases are to be considered by the animator,
right click to Set Every 2, 3,……, 10 cases. This is particularly useful for
quasi-static or transient analyses where only some time steps are to be
animated.
Also Shift-clicking the results cases allow a range of cases to be turned on
or off at once.
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Results Options
Results/Options includes a number of different
settings that can be applied to Strand7 results. The
Show/Hide tab includes the ability to specify how
elements are shown when they have no results; e.g.
inactive point contact elements, patch plates, postprocessing number settings.
The Staging tab allows you to decide how the
displacement contours should be shown.
The Harmonic tab allows for the results to be
specified as either the total or relative to the base
excitation input.
The Combinations and Envelopes tabs allow you
to set whether to automatically generate these
results, save them, etc.
The Other tab allows you to specify whether the
GNL displacements should be added to the initial
undeformed model display, for example when a
GNL solution is used as an initial condition for the
natural frequency solver.
Results/Options – Numbers
The Numbers tab specifies how numbers for
results are displayed, e.g. the number of decimal
places. Previously this was located in View/Options
along side the pre-processing number settings.
The Numbers tab also allows the units for rotation
to be set as either Degree or Radian.
It allows the Strain measure to be set as either Unit
strain, % strain or Microstrain.
Results Listings Hide Zeros
The option to Hide Zeros is available by right-clicking the Results Listing spreadsheet. This works the same as for
the nonlinear load increments table.
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Peek Tool Font Size
Right clicking the peek tool window allows the font size to be set. The options are Small Text, Medium Text and
Large Text.
Results Listing Multi-Select
When multi-case is selected in the results listing, Shift-clicking allows a range of load cases to be turned on or off at
once.
Reference Displacement
The new Results/Reference Displacement menu allows you to select a Reference Result Case and then all
displacements will be presented with reference to that case. This can be useful in soil analyses where the
displacements relative to the initial settlement are of interest.
Transverse Shear Stress
Distribution
The transverse shear stress distribution is now
available for standard section beams and plate
elements. In addition to reporting the
highest shear stress across a section, the
distribution is also available in the results.
Spent and Stored Energy
In addition to the Strain Energy Density, the
total energy expended by and the amount of
energy stored in the element are now also
reported in the results.
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New Graphing Options
Graphs in Cylindrical System
A polar UCS can now be used to select nodes or elements to be
plotted on a Vs Position graph.
Graphs on Cutting Plane
Similar to using a cylindrical coordinate system, a cutting plane can be defined when graphing to select the nodes or
elements you wish to plot. All nodes or elements that lie within this cutting plane will have their results plotted.
Graph Integrals
When calculating integrals under a graph in Strand7 there are two options given for Length×Area, (G) and (L). G
stands for global and the integral considers the full range of the graphs as the length. L stands for local and in this
case the integral is calculated based on the length of each individual graph. There will only be a difference between
these two values when there are multiple plots on the one graph and each has a different X range.
Copy Graphs
Ctrl-Shift-C will copy graphs from the graph window to the Windows clipboard without including the window
border.
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Multiple Load Case Selection
When creating a graph Vs Position or Vs Series of Points you can
generate it for multiple load cases in one step. A line will be drawn on
the graph for each load case selected with a corresponding entry in the
legend given.
Beam Intersection
When plotting a graph Vs Position for a beam, the option
to Show… Intersection is available. This will plot the
value where the line intersects the beam element.
A useful product of this is the ability to plot a bending
moment diagram for a beam element. If you select the
position from one end of the beam to the other (along the
3 axis) the values plotted will be the values at each of the
beam slices, as set in the Results Settings dialog, producing
a bending moment plot for that beam.
Brick Intersection
When plotting a graph Vs Position on a brick element, if the line cuts through the middle of a brick element an
intersection point will be detected. Previously this was only the case if the line cut the brick edge.
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New API Functions
API
Around 800 new functions have been added to the popular Strand7 API. In addition to functions that operate on
the new functionality in Release 2.4, there are new functions in the following general areas:
1. Functions for import and export.
This includes importing/exporting geometry and other file formats supported by Strand7.
2. Functions for executing the automeshing tools.
3. Functions for graphically displaying the Strand7 model via the API; this is similar to opening the model
window.
4. Functions for generating Strand7 results files from scratch.
This will be useful for anyone who wants to post-process the results of another program using Strand7.
5. A function to generate Strand7 Bitmaps.
6. In addition to the previously available headers, (Delphi, Micrsoft Visual C++, Borland Builder, Compaq
Visual Fortran, Microsft Visual Basic – including VBA), the API also ships with headers for Matlab 7.3 and
Microsoft Visual C++.NET.
7. Ability to query the version of the API using a new function call.
8. Ability to release the occupied NetHASP Licence whenever the API functions are no longer required by the
rest of the routines.
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General Functionality and Improvements
Default Options
The Save as Defaults option available in many dialogs in previous releases of
Strand7 has been replaced with a new Defaults menu. In the new setup you will be
able to save the current settings to default (Save as User Defaults), set all the
options to previously saved defaults (Set User Defaults) or revert back to original
Strand7 defaults (Set Factory Defaults). A number of other dialogs now also
feature the option to save the defaults.
Help File
File/Preferences allows the user to specify the location of the Strand7 Help file.
Online Editor Paste as New
Similar to the current ability to Paste As New nodal coordinates it is now possible to Paste As New elements in the
Online Editor. This will paste information such as the property type, thickness and node numbers. You will need to
remember that for the element to exist the corresponding nodes and their coordinates must already exist in the
model.
Main Toolbar State
Strand7 will remember the state of the main toolbar, e.g. if it is maximised, and use this the next time you run the
program.
Hide Model Window Border
Choose to hide the Model Window border so that it sits flush against the main toolbar.
Normalise Model Window
Two options now exist to normalise the model window in Strand7, Normalise All and Normalise model window
on open. This means that swapping between horizontal or vertical tiling and normalised windows is now a one step
operation. Choose Window/Normalise All to normalise all model windows at once or Window/Normalise to
normalise a specific model window. Or choose File/Preferences/Normalise model window on open to ensure
that all Strand7 models opened are normalised. The Normalise option is also available via the right-click operation
within the specific model window.
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What’s New in Strand7 Release 2.4
IFPOS(), IFNEG()
Two new functions are available for use as the general
numeric input in Strand7. Strand7 has always allowed
equations to be entered in place of numerical values, and
also equations with variables, e.g. entering 1000*9.81*Z is
a very easy way to apply hydrostatic pressure along the Z
axis for any number of selected elements. Now with the
IFPOS() and IFNEG() functions, these attributes can be
applied conditionally. For example, if you have a ship
sitting in water, you could make the water line the Z=0
coordinate. If you wish to assign hydrostatic water
pressure only to those sections of the ship that are below
the waterline then you could use IFNEG(Z) as part of the
pressure equation to ensure that only those elements with a
negative Z coordinate, i.e. those elements in the water, are
assigned a pressure.
IFPOSB(), IFNEGB()
Further to the previous new functions are binary extensions of these. The B in these two functions stands for binary.
This allows for a return value of 1 if the statement is true and 0 if the statement is negative. For example,
IFPOSB(x) will use 1 in the equation if x is positive but 0 if x is negative.
Random Number
A random number can be generated as part of an equation in Strand7 R2.4. Using rand(x) in a dialog box will
generate a random number between zero and x.
ID and N
The ID attribute or number of a node or element can be used as variables in equations. If ID is used in the
equation, the node or element ID will be used as the value. If N is used in the equation then the node or element
number will be used, e.g. to make each plate in a model have the same property number as its element number you
would choose Attributes/Plate/Property Type and enter N as the property number.
Factor vs Position Table Parsing
A Factor vs Position table can be created, which can then be referenced in an equation
to apply loads, etc, to the structure. The equation is written in the form PT[Table ID
Number](x). In the figure on the right the equation looks at Factor vs Position table
1, and then evaluates the y-intercept at position x, which in this case is 4.
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What’s New in Strand7 Release 2.4
Group Updates
The group tree now gives a tally of the number of entities that are
assigned to the selected group. A useful aspect of this is that when
elements are assigned to a group, it can be confirmed by checking
that the tallies have changed.
A new feature has also been added for models that are not shown in
group colour, e.g. property colour, global colour, etc. Now when
an element is assigned to a group it will briefly be drawn in the
colour of the group before reverting back to its original colour.
This provides further feedback that you have correctly assigned the
groups.
Multiple Zoom and Pan
To continuously repeat pan or zoom window operations on a model hold down Ctrl when selecting any of these
three viewing options. The selected operation will stay active until deselected or another operation is performed.
Retrieve Property Type
Use Ctrl-Click when part way through creating a new element to retrieve the property type of an existing one.
Animator Changes
The Strand7 results animator can be used to create an animation of a single result
case or a number of specific result cases in a model. This is particularly useful if you
want to view an animation of a single nonlinear load increment, e.g. you have used
the Nonlinear solver to create a number of load case combinations.
Additional settings are included in the animator itself. A step backward button is
included in addition to step forward. Also, when the animation is paused, the arrow
keys on the keyboard can be used to step forward and backwards. Home and Page
Up will jump to the first frame and End and Page Down will jump to the last frame.
Vertex Paste Anchor
Vertices can be used as anchor points when using the Copy and Paste functions in a model.
Snap Grid/Vertices Reference Selection
Snap grid points and vertices can be used as references in the tools menu, e.g. Set by Points in Copy/by Increment,
Point on the plane in Extrude/by Projection/to Plane, Point on the Plane in Mirror, etc. The label defining the
point, e.g. N for node, V for vertex and G for grid point will automatically update depending on the entity type
selected.
Opening Strand7 Files
Multiple Strand7 files can be opened at once by holding Ctrl when selecting the files. It is now also possible to have
10 files open simultaneously.
Filter On in Online Editor
Similar to the results listings nodes or elements can be filtered in the online editor. This provides a method for only
showing specific nodes or elements via their selection in the model window.
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What’s New in Strand7 Release 2.4
Properties in Online Editor
A property column is now available in the Online Editor when viewing element attributes. This allows for easier
sorting and filtering. The property column was previously only available in the element connection section of the
Online Editor.
Rename Increments
By right-clicking the nonlinear load increment table or combine results files grid the increment or case names can be
automatically changed via Rename Increments or Rename Cases.
BXS
When a beam section is
generated using Make
Beam Section, the Shear
Centre, Warping
Constant, and the Radius
Area Integral of the
beam are calculated.
Relative Shear Stress 1
and 2 and Torque
stresses can also be
shown on the cross
section.
The BXS generator now
also accepts link elements
as part of the mesh.
These elements can be
used to provide shear
compatibility between
independent parts of a
cross section, e.g. for a
mirrored section the
links generate a J that
twists both sections as
one, instead of just twice
the J of one section.
Cut-Copy-Paste
Ctrl-X (Cut), Ctrl-C (Copy) and Ctrl-V (Paste) are active in Edit boxes when they are focused.
Dynamic Rotate Keyboard Functions
When dynamic rotate is active for a model the following keyboard shortcuts are available:
F3 – centres and rescales the model.
Left and Right Arrows – rotates the model about screen Y.
Up and Down Arrows – rotates the model about screen X.
Page Up and Page Down – rotates the model anticlockwise or clockwise about screen Z.
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What’s New in Strand7 Release 2.4
Free Cylindrical UCS
A new type of cylindrical UCS called Free is now available. This allows you to
create a cylindrical UCS by selecting three points on a circle.
Model Window Status Bar Shortcuts
The model window status bar has a number of shortcuts
available.
•
•
•
•
•
•
Click Nodes or Vertices to activate the Whiteboard.
Click Beams, Plates, Bricks, Links, Faces or Paths to see
a quantitative list of the types of these in the model each in
the model.
Click units to change the units in the model.
Click angles to activate the View/Angles dialog.
Click displacement scale (when results are open) to activate
the displacement scale dialog.
Click Default Group to activate the group tree and set a
new default group.
Spreadsheet Column Separator
The column separator in spreadsheets, e.g. the Online Editor, can be a comma or a period depending on the
computers regional settings. For example in Australia or the US the separator is a comma as ‘.’ is for decimal places
while in Europe the separator is a period as ‘,’ is for decimal places.
Entity Inspector for any Entity
By holding down Shift+Ctrl when hovering over an entity, the Entity Inspector will ignore the active and inactive
entity toggles and show the window for the entity closest to the cursor.
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What’s New in Strand7 Release 2.4
Post-Processor Warnings
A number of warning messages will now be generated
when post-processing in Strand7. For example, when
midplane stresses are contoured a warning message will
be generated detailing that peak stresses may be missed
if the +z and –z stresses are not also checked.
These warning messages can be disabled via the
Warnings tab in File/Preferences.
Laminate Property Numbering
Property/Laminate is now referenced by a number as well as a name.
Null Elements
Zero element property type is now allowed in a model. This allows null elements to be inserted in a model file to
ensure that the element numbering does not change when the model is packed. Elements with zero property type
are not packed.
Save and Backup File
A new backup option is available in the File/Preferences/Backups. This option will save the file as usual and
create a copy of the file with suffix “(xxx)”, where xxx is a number. This number keeps incrementing so you’ll have
a full history of the models you created/saved.
Use Library Name
An option to replace the default property name, e.g. “Property 1”, automatically when importing data from the
library is available in:
•
Beam Section Library,
•
Ply Material Library,
•
Creep Data Library, and
•
Moving Load Path Template Library.
User-Defined Gauss Point Contour
User-Defined Contour can be selected under View/Entity Display/Contour Type/User Defined (file). The Gauss
Point contour file is now allowed to use one Gauss Point value per element.
UCS Changes on Undo List
Changes to the User Coordinate Systems are now included on the Undo list.
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What’s New in Strand7 Release 2.4
Log File Data Filter
An improved data filter in the results log file viewer is available.
Apply View Angle
The View/Angle dialog box now has an Apply
button, which allows changes to be made
without closing the dialog box.
Show Property Type Update
The View/Show by Type/Property dialog box now has an Auto-Update option similar to the Groups dialog. With
this option set, the property display will change without the need to click Apply.
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What’s New in Strand7 Release 2.4
Installation
Common Setup Options
When using St7Config.exe to setup an installation of Strand7
on a Server and/or Client a Common tab has been included
that allows the control of timeouts.
Set Idle Time
When using St7Config.exe to setup an
installation of Strand7 on a Server an
option is available to set the maximum
idle time before licence is released. This
allows a licence to be freed if it has been
occupied and left idle for too long.
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